diff --git a/src/button/ReactionToggleButton.test.tsx b/src/button/ReactionToggleButton.test.tsx
index 5a3b1ce3..bd9c115b 100644
--- a/src/button/ReactionToggleButton.test.tsx
+++ b/src/button/ReactionToggleButton.test.tsx
@@ -79,7 +79,7 @@ test("Can raise hand", async () => {
   expect(container).toMatchSnapshot();
 });
 
-test.only("Can lower hand", async () => {
+test("Can lower hand", async () => {
   const user = userEvent.setup();
   const { vm, rtcSession } = getBasicCallViewModelEnvironment([local, alice]);
   const { getByLabelText, container } = render(
@@ -95,6 +95,7 @@ test.only("Can lower hand", async () => {
       reactions: {},
     });
   });
+  await user.click(getByLabelText("common.reactions"));
   await user.click(getByLabelText("action.lower_hand"));
   expect(rtcSession.room.client.redactEvent).toHaveBeenCalledWith(
     undefined,
@@ -118,63 +119,55 @@ test.only("Can lower hand", async () => {
 
 test("Can react with emoji", async () => {
   const user = userEvent.setup();
-  const room = new MockRoom(memberUserIdAlice);
-  const rtcSession = new MockRTCSession(room, membership);
+  const { vm, rtcSession } = getBasicCallViewModelEnvironment([local, alice]);
   const { getByLabelText, getByText } = render(
-    <TestComponent rtcSession={rtcSession} />,
+    <TestComponent vm={vm} rtcSession={rtcSession} />,
   );
   await user.click(getByLabelText("common.reactions"));
   await user.click(getByText("🐶"));
-  expect(room.testSentEvents).toEqual([
-    [
-      undefined,
-      ElementCallReactionEventType,
-      {
-        "m.relates_to": {
-          event_id: memberEventAlice,
-          rel_type: "m.reference",
-        },
-        name: "dog",
-        emoji: "🐶",
+  expect(rtcSession.room.client.sendEvent).toHaveBeenCalledWith(
+    undefined,
+    ElementCallReactionEventType,
+    {
+      "m.relates_to": {
+        event_id: localRtcMember.eventId,
+        rel_type: "m.reference",
       },
-    ],
-  ]);
+      name: "dog",
+      emoji: "🐶",
+    },
+  );
 });
 
 test("Can fully expand emoji picker", async () => {
   const user = userEvent.setup();
-  const room = new MockRoom(memberUserIdAlice);
-  const rtcSession = new MockRTCSession(room, membership);
-  const { getByText, container, getByLabelText } = render(
-    <TestComponent rtcSession={rtcSession} />,
+  const { vm, rtcSession } = getBasicCallViewModelEnvironment([local, alice]);
+  const { getByLabelText, container, getByText } = render(
+    <TestComponent vm={vm} rtcSession={rtcSession} />,
   );
   await user.click(getByLabelText("common.reactions"));
   await user.click(getByLabelText("action.show_more"));
   expect(container).toMatchSnapshot();
   await user.click(getByText("🦗"));
-
-  expect(room.testSentEvents).toEqual([
-    [
-      undefined,
-      ElementCallReactionEventType,
-      {
-        "m.relates_to": {
-          event_id: memberEventAlice,
-          rel_type: "m.reference",
-        },
-        name: "crickets",
-        emoji: "🦗",
+  expect(rtcSession.room.client.sendEvent).toHaveBeenCalledWith(
+    undefined,
+    ElementCallReactionEventType,
+    {
+      "m.relates_to": {
+        event_id: localRtcMember.eventId,
+        rel_type: "m.reference",
       },
-    ],
-  ]);
+      name: "crickets",
+      emoji: "🦗",
+    },
+  );
 });
 
 test("Can close reaction dialog", async () => {
   const user = userEvent.setup();
-  const room = new MockRoom(memberUserIdAlice);
-  const rtcSession = new MockRTCSession(room, membership);
+  const { vm, rtcSession } = getBasicCallViewModelEnvironment([local, alice]);
   const { getByLabelText, container } = render(
-    <TestComponent rtcSession={rtcSession} />,
+    <TestComponent vm={vm} rtcSession={rtcSession} />,
   );
   await user.click(getByLabelText("common.reactions"));
   await user.click(getByLabelText("action.show_more"));
diff --git a/src/button/ReactionToggleButton.tsx b/src/button/ReactionToggleButton.tsx
index 273436c2..6d75fa60 100644
--- a/src/button/ReactionToggleButton.tsx
+++ b/src/button/ReactionToggleButton.tsx
@@ -184,7 +184,7 @@ export function ReactionToggleButton({
     vm.handsRaised.pipe(map((v) => !!v[identifier])),
   );
   const canReact = useObservableState(
-    vm.reactions.pipe(map((v) => !!v[identifier])),
+    vm.reactions.pipe(map((v) => !v[identifier])),
   );
 
   useEffect(() => {
diff --git a/src/button/__snapshots__/ReactionToggleButton.test.tsx.snap b/src/button/__snapshots__/ReactionToggleButton.test.tsx.snap
index b1b5df35..5dce0977 100644
--- a/src/button/__snapshots__/ReactionToggleButton.test.tsx.snap
+++ b/src/button/__snapshots__/ReactionToggleButton.test.tsx.snap
@@ -9,7 +9,7 @@ exports[`Can close reaction dialog 1`] = `
     aria-disabled="false"
     aria-expanded="true"
     aria-haspopup="true"
-    aria-labelledby=":r9l:"
+    aria-labelledby=":rav:"
     class="_button_i91xf_17 _has-icon_i91xf_66 _icon-only_i91xf_59"
     data-kind="primary"
     data-size="lg"
@@ -43,7 +43,7 @@ exports[`Can fully expand emoji picker 1`] = `
     aria-disabled="false"
     aria-expanded="true"
     aria-haspopup="true"
-    aria-labelledby=":r6c:"
+    aria-labelledby=":r7m:"
     class="_button_i91xf_17 _has-icon_i91xf_66 _icon-only_i91xf_59"
     data-kind="primary"
     data-size="lg"
@@ -68,35 +68,6 @@ exports[`Can fully expand emoji picker 1`] = `
 </div>
 `;
 
-exports[`Can lower hand 1`] = `
-<div>
-  <button
-    aria-disabled="false"
-    aria-expanded="false"
-    aria-haspopup="true"
-    aria-labelledby=":r36:"
-    class="_button_i91xf_17 raisedButton _has-icon_i91xf_66 _icon-only_i91xf_59"
-    data-kind="primary"
-    data-size="lg"
-    role="button"
-    tabindex="0"
-  >
-    <svg
-      aria-hidden="true"
-      fill="currentColor"
-      height="24"
-      viewBox="0 0 24 24"
-      width="24"
-      xmlns="http://www.w3.org/2000/svg"
-    >
-      <path
-        d="M11 3a1 1 0 1 1 2 0v8.5a.5.5 0 0 0 1 0V4a1 1 0 1 1 2 0v10.2l3.284-2.597a1.081 1.081 0 0 1 1.47 1.577c-.613.673-1.214 1.367-1.818 2.064-1.267 1.463-2.541 2.934-3.944 4.235A6 6 0 0 1 5 15V7a1 1 0 0 1 2 0v5.5a.5.5 0 0 0 1 0V4a1 1 0 0 1 2 0v7.5a.5.5 0 0 0 1 0V3Z"
-      />
-    </svg>
-  </button>
-</div>
-`;
-
 exports[`Can open menu 1`] = `
 <div
   aria-hidden="true"
@@ -137,7 +108,7 @@ exports[`Can raise hand 1`] = `
     aria-disabled="false"
     aria-expanded="false"
     aria-haspopup="true"
-    aria-labelledby=":r0:"
+    aria-labelledby=":r1j:"
     class="_button_i91xf_17 raisedButton _has-icon_i91xf_66 _icon-only_i91xf_59"
     data-kind="primary"
     data-size="lg"
diff --git a/src/room/GroupCallView.test.tsx b/src/room/GroupCallView.test.tsx
index ea2cc5cf..41e587a7 100644
--- a/src/room/GroupCallView.test.tsx
+++ b/src/room/GroupCallView.test.tsx
@@ -29,6 +29,7 @@ import { GroupCallView } from "./GroupCallView";
 import { leaveRTCSession } from "../rtcSessionHelpers";
 import { type WidgetHelpers } from "../widget";
 import { LazyEventEmitter } from "../LazyEventEmitter";
+import { RelationsContainer } from "matrix-js-sdk/src/models/relations-container";
 
 vitest.mock("../soundUtils");
 vitest.mock("../useAudioContext");
@@ -85,6 +86,12 @@ function createGroupCallView(widget: WidgetHelpers | null): {
     getRoom: (rId) => (rId === roomId ? room : null),
   } as Partial<MatrixClient> as MatrixClient;
   const room = mockMatrixRoom({
+    relations: {
+      getChildEventsForEvent: () =>
+        vitest.mocked({
+          getRelations: () => [],
+        }),
+    } as unknown as RelationsContainer,
     client,
     roomId,
     getMember: (userId) => roomMembers.get(userId) ?? null,
diff --git a/src/room/InCallView.tsx b/src/room/InCallView.tsx
index 9e8ad23a..f5af9a41 100644
--- a/src/room/InCallView.tsx
+++ b/src/room/InCallView.tsx
@@ -115,7 +115,6 @@ export const ActiveCall: FC<ActiveCallProps> = (props) => {
     [connState],
   );
   const [vm, setVm] = useState<CallViewModel | null>(null);
-  const reactions = useReactions();
 
   useEffect(() => {
     return (): void => {
@@ -126,10 +125,6 @@ export const ActiveCall: FC<ActiveCallProps> = (props) => {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, []);
 
-  useEffect(() => {
-    vm?.updateReactions(reactions);
-  }, [vm, reactions]);
-
   useEffect(() => {
     if (livekitRoom !== undefined) {
       const vm = new CallViewModel(
@@ -147,7 +142,7 @@ export const ActiveCall: FC<ActiveCallProps> = (props) => {
 
   return (
     <RoomContext.Provider value={livekitRoom}>
-      <ReactionsProvider rtcSession={props.rtcSession}>
+      <ReactionsProvider vm={vm} rtcSession={props.rtcSession}>
         <InCallView
           {...props}
           vm={vm}
diff --git a/src/state/CallViewModel.test.ts b/src/state/CallViewModel.test.ts
index 0dbcffaa..93daba12 100644
--- a/src/state/CallViewModel.test.ts
+++ b/src/state/CallViewModel.test.ts
@@ -689,63 +689,117 @@ it("should show at least one tile per MatrixRTCSession", () => {
   });
 });
 
-// TODO: Add presenters and speakers?
-it("should rank raised hands above video feeds and below speakers and presenters", () => {
-  withTestScheduler(({ schedule, expectObservable }) => {
-    // There should always be one tile for each MatrixRTCSession
-    const expectedLayoutMarbles = "a";
-
+it("Should correctly handle a raised hand event", () => {
+  withTestScheduler(({ expectObservable }) => {
+    const date = new Date();
     withCallViewModel(
-      of([aliceParticipant, bobParticipant]),
-      of([aliceRtcMember, bobRtcMember]),
+      of([]),
+      of([]),
       of(ConnectionState.Connected),
       new Map(),
       (vm) => {
-        schedule("ah", {
-          a: () => {
-            // We imagine that only three tiles (the first three) will be visible
-            // on screen at a time
-            vm.layout.subscribe((layout) => {
-              console.log(layout);
-              if (layout.type === "grid") {
-                for (let i = 0; i < layout.grid.length; i++)
-                  layout.grid[i].setVisible(i <= 1);
-              }
-            });
-          },
-          h: () => {
-            vm.updateReactions({
-              reactions: {},
-              raisedHands: {
-                [`${bobRtcMember.sender}:${bobRtcMember.deviceId}`]: new Date(),
-              },
-            });
+        vm.addHandRaised(alice.userId, date);
+        expectObservable(vm.handsRaised).toBe("a", {
+          a: {
+            [alice.userId]: date,
           },
         });
-        expectObservable(summarizeLayout(vm.layout)).toBe(
-          expectedLayoutMarbles,
-          {
-            a: {
-              type: "grid",
-              spotlight: undefined,
-              grid: [
-                "local:0",
-                "@bob:example.org:BBBB:0",
-                "@alice:example.org:AAAA:0",
-              ],
-            },
-            h: {
-              type: "grid",
-              spotlight: undefined,
-              grid: [
-                "local:0",
-                "@bob:example.org:BBBB:0",
-                "@alice:example.org:AAAA:0",
-              ],
-            },
+        expectObservable(vm.handRaised).toBe("a", {
+          a: {
+            value: 1,
+            playSounds: true,
           },
-        );
+        });
       },
     );
   });
 });
+
+it.only("Should correctly handle a lowered hand event", () => {
+  const date = new Date();
+  withTestScheduler(({ expectObservable }) => {
+    withCallViewModel(
+      of([]),
+      of([]),
+      of(ConnectionState.Connected),
+      new Map(),
+      (vm) => {
+        vm.addHandRaised(alice.userId, date);
+        vm.addHandRaised(bob.userId, date);
+        expectObservable(vm.handsRaised).toBe("a", {
+          a: {
+            [bob.userId]: date,
+          },
+          b: {
+            [bob.userId]: date,
+          },
+        });
+      },
+    );
+  });
+});
+
+// TODO: Add presenters and speakers?
+it.todo(
+  "should rank raised hands above video feeds and below speakers and presenters",
+  () => {
+    withTestScheduler(({ schedule, expectObservable }) => {
+      // There should always be one tile for each MatrixRTCSession
+      const expectedLayoutMarbles = "a";
+
+      withCallViewModel(
+        of([aliceParticipant, bobParticipant]),
+        of([aliceRtcMember, bobRtcMember]),
+        of(ConnectionState.Connected),
+        new Map(),
+        (vm) => {
+          schedule("ah", {
+            a: () => {
+              // We imagine that only three tiles (the first three) will be visible
+              // on screen at a time
+              vm.layout.subscribe((layout) => {
+                console.log(layout);
+                if (layout.type === "grid") {
+                  for (let i = 0; i < layout.grid.length; i++)
+                    layout.grid[i].setVisible(i <= 1);
+                }
+              });
+            },
+            h: () => {
+              vm.updateReactions({
+                reactions: {},
+                raisedHands: {
+                  [`${bobRtcMember.sender}:${bobRtcMember.deviceId}`]:
+                    new Date(),
+                },
+              });
+            },
+          });
+          expectObservable(summarizeLayout(vm.layout)).toBe(
+            expectedLayoutMarbles,
+            {
+              a: {
+                type: "grid",
+                spotlight: undefined,
+                grid: [
+                  "local:0",
+                  "@bob:example.org:BBBB:0",
+                  "@alice:example.org:AAAA:0",
+                ],
+              },
+              h: {
+                type: "grid",
+                spotlight: undefined,
+                grid: [
+                  "local:0",
+                  "@bob:example.org:BBBB:0",
+                  "@alice:example.org:AAAA:0",
+                ],
+              },
+            },
+          );
+        },
+      );
+    });
+  },
+);
diff --git a/src/state/CallViewModel.ts b/src/state/CallViewModel.ts
index ecd1ef62..79dbdcfc 100644
--- a/src/state/CallViewModel.ts
+++ b/src/state/CallViewModel.ts
@@ -1146,23 +1146,61 @@ export class CallViewModel extends ViewModel {
   );
 
   private readonly handsRaisedSubject = new BehaviorSubject<
-    Record<string, Date>
-  >({});
+    { userId: string; date: Date | null }[]
+  >([]);
   private readonly reactionsSubject = new BehaviorSubject<
-    Record<string, ReactionOption>
-  >({});
+    { userId: string; reaction: ReactionOption; ttl: number }[]
+  >([]);
 
-  public readonly handsRaised = this.handsRaisedSubject.asObservable();
-  public readonly reactions = this.reactionsSubject.asObservable();
-
-  public updateReactions(data: {
-    raisedHands: Record<string, Date>;
-    reactions: Record<string, ReactionOption>;
-  }): void {
-    this.handsRaisedSubject.next(data.raisedHands);
-    this.reactionsSubject.next(data.reactions);
+  public addHandRaised(userId: string, date: Date) {
+    this.handsRaisedSubject.next([{ userId, date }]);
   }
 
+  public removeHandRaised(userId: string, date: Date | null) {
+    this.handsRaisedSubject.next([{ userId, date }]);
+  }
+
+  public addReaction(userId: string, reaction: ReactionOption, ttl: number) {
+    this.reactionsSubject.next([{ userId, reaction, ttl }]);
+  }
+
+  public readonly reactions = this.reactionsSubject
+    .pipe(
+      scan<
+        { userId: string; reaction: ReactionOption; ttl: number }[],
+        Record<string, { reaction: ReactionOption; ttl: number }>
+      >((acc, value) => {
+        for (const { userId, reaction, ttl } of value) {
+          acc[userId] = { reaction, ttl };
+        }
+        return acc;
+      }, {}),
+    )
+    .pipe(
+      map((v) =>
+        Object.fromEntries(
+          Object.entries(v).map(([a, { reaction }]) => [a, reaction]),
+        ),
+      ),
+    );
+
+  public readonly handsRaised = this.handsRaisedSubject.pipe(
+    scan<{ userId: string; date: Date | null }[], Record<string, Date>>(
+      (acc, value) => {
+        for (const { userId, date } of value) {
+          if (date) {
+            acc[userId] = date;
+          } else {
+            delete acc[userId];
+          }
+        }
+        console.log("handsRaised", acc);
+        return acc;
+      },
+      {},
+    ),
+  );
+
   /**
    * Emits an array of reactions that should be visible on the screen.
    */
diff --git a/src/useReactions.test.tsx b/src/useReactions.test.tsx
index 508be5a1..187c1b7a 100644
--- a/src/useReactions.test.tsx
+++ b/src/useReactions.test.tsx
@@ -15,8 +15,6 @@ import {
   createHandRaisedReaction,
   createRedaction,
   MockRoom,
-  ReactionsMockRTCSession,
-  TestReactionsWrapper,
 } from "./utils/testReactions";
 
 const memberUserIdAlice = "@alice:example.org";
diff --git a/src/useReactions.tsx b/src/useReactions.tsx
index 0acdcc7b..025ff073 100644
--- a/src/useReactions.tsx
+++ b/src/useReactions.tsx
@@ -35,17 +35,10 @@ import {
   ReactionSet,
 } from "./reactions";
 import { useLatest } from "./useLatest";
+import { CallViewModel } from "./state/CallViewModel";
 
 interface ReactionsContextType {
-  /**
-   * identifier (userId:deviceId => Date)
-   */
-  raisedHands: Record<string, Date>;
   supportsReactions: boolean;
-  /**
-   * reactions (userId:deviceId => Date)
-   */
-  reactions: Record<string, ReactionOption>;
   toggleRaisedHand: () => Promise<void>;
   sendReaction: (reaction: ReactionOption) => Promise<void>;
 }
@@ -79,15 +72,23 @@ export const useReactions = (): ReactionsContextType => {
   return context;
 };
 
+/**
+ * HS plan:
+ *  Provider should publish new hand raised, reaction events to CallViewModel
+ *  Provider should listen for new events from CVM
+ */
+
 /**
  * Provider that handles raised hand reactions for a given `rtcSession`.
  */
 export const ReactionsProvider = ({
   children,
   rtcSession,
+  vm,
 }: {
   children: ReactNode;
   rtcSession: MatrixRTCSession;
+  vm: CallViewModel;
 }): JSX.Element => {
   const [raisedHands, setRaisedHands] = useState<
     Record<string, RaisedHandInfo>
@@ -103,6 +104,15 @@ export const ReactionsProvider = ({
   const latestMemberships = useLatest(memberships);
   const latestRaisedHands = useLatest(raisedHands);
 
+  useEffect(() => {
+    vm.updateReactions({
+      raisedHands: Object.fromEntries(
+        Object.entries(raisedHands).map(([uid, data]) => [uid, data.time]),
+      ),
+      reactions,
+    });
+  }, [memberships, raisedHands]);
+
   const myMembershipEvent = useMemo(
     () =>
       memberships.find(
@@ -121,14 +131,6 @@ export const ReactionsProvider = ({
     {},
   );
 
-  // Reduce the data down for the consumers.
-  const resultRaisedHands = useMemo(
-    () =>
-      Object.fromEntries(
-        Object.entries(raisedHands).map(([uid, data]) => [uid, data.time]),
-      ),
-    [raisedHands],
-  );
   const addRaisedHand = useCallback((userId: string, info: RaisedHandInfo) => {
     setRaisedHands((prevRaisedHands) => ({
       ...prevRaisedHands,
@@ -394,7 +396,7 @@ export const ReactionsProvider = ({
 
   const sendReaction = useCallback(
     async (reaction: ReactionOption) => {
-      if (!myMembershipIdentifier || !reactions[myMembershipIdentifier]) {
+      if (!myMembershipIdentifier || reactions[myMembershipIdentifier]) {
         // We're still reacting
         return;
       }
@@ -420,9 +422,7 @@ export const ReactionsProvider = ({
   return (
     <ReactionsContext.Provider
       value={{
-        raisedHands: resultRaisedHands,
         supportsReactions,
-        reactions,
         toggleRaisedHand,
         sendReaction,
       }}
diff --git a/src/utils/testReactions.tsx b/src/utils/testReactions.tsx
index 6d57f8d5..56e9fa86 100644
--- a/src/utils/testReactions.tsx
+++ b/src/utils/testReactions.tsx
@@ -5,7 +5,6 @@ SPDX-License-Identifier: AGPL-3.0-only
 Please see LICENSE in the repository root for full details.
 */
 
-import { type PropsWithChildren, type ReactNode } from "react";
 import { randomUUID } from "crypto";
 import EventEmitter from "events";
 import { type MatrixClient } from "matrix-js-sdk/src/client";
@@ -16,52 +15,11 @@ import {
   EventTimelineSet,
   type Room,
 } from "matrix-js-sdk/src/matrix";
-import {
-  type MatrixRTCSession,
-  MatrixRTCSessionEvent,
-} from "matrix-js-sdk/src/matrixrtc";
-
-import { ReactionsProvider } from "../useReactions";
 import {
   type ECallReactionEventContent,
   ElementCallReactionEventType,
   type ReactionOption,
 } from "../reactions";
-import { MockRTCSession } from "./test";
-
-// export class ReactionsMockRTCSession extends EventEmitter {
-//   public memberships: {
-//     sender: string;
-//     eventId: string;
-//     createdTs: () => Date;
-//   }[];
-
-//   public constructor(
-//     public readonly room: MockRoom,
-//     membership: Record<string, string>,
-//   ) {
-//     super();
-//     this.memberships = Object.entries(membership).map(([eventId, sender]) => ({
-//       sender,
-//       eventId,
-//       createdTs: (): Date => new Date(),
-//     }));
-//   }
-
-//   public testRemoveMember(userId: string): void {
-//     this.memberships = this.memberships.filter((u) => u.sender !== userId);
-//     this.emit(MatrixRTCSessionEvent.MembershipsChanged);
-//   }
-
-//   public testAddMember(sender: string): void {
-//     this.memberships.push({
-//       sender,
-//       eventId: `!fake-${randomUUID()}:event`,
-//       createdTs: (): Date => new Date(),
-//     });
-//     this.emit(MatrixRTCSessionEvent.MembershipsChanged);
-//   }
-// }
 
 export function createHandRaisedReaction(
   parentMemberEvent: string,