diff --git a/apps/web/src/components/hq/HQWaitingForInputSection.tsx b/apps/web/src/components/hq/HQWaitingForInputSection.tsx
deleted file mode 100644
index 6a23e33..0000000
--- a/apps/web/src/components/hq/HQWaitingForInputSection.tsx
+++ /dev/null
@@ -1,65 +0,0 @@
-import { useNavigate } from '@tanstack/react-router'
-import { Card } from '@/components/ui/card'
-import { Button } from '@/components/ui/button'
-import {
-  Tooltip,
-  TooltipTrigger,
-  TooltipContent,
-  TooltipProvider,
-} from '@/components/ui/tooltip'
-import { formatRelativeTime } from '@/lib/utils'
-import type { WaitingForInputItem } from './types'
-
-interface Props {
-  items: WaitingForInputItem[]
-}
-
-export function HQWaitingForInputSection({ items }: Props) {
-  const navigate = useNavigate()
-
-  return (
-    <div className="space-y-3">
-      <h2 className="text-sm font-medium text-muted-foreground uppercase tracking-wide">
-        Waiting for Input
-      </h2>
-      <div className="space-y-2">
-        {items.map((item) => {
-          const truncated =
-            item.questionText.slice(0, 120) +
-            (item.questionText.length > 120 ? '…' : '')
-
-          return (
-            <Card key={item.agentId} className="p-4 flex items-center justify-between gap-4">
-              <div className="min-w-0 flex-1">
-                <p className="font-bold text-sm">
-                  {item.agentName}
-                  {item.initiativeName && (
-                    <span className="font-normal text-muted-foreground"> · {item.initiativeName}</span>
-                  )}
-                </p>
-                <TooltipProvider>
-                  <Tooltip>
-                    <TooltipTrigger asChild>
-                      <p className="text-sm text-muted-foreground truncate">{truncated}</p>
-                    </TooltipTrigger>
-                    <TooltipContent forceMount>{item.questionText}</TooltipContent>
-                  </Tooltip>
-                </TooltipProvider>
-                <p className="text-xs text-muted-foreground">
-                  waiting {formatRelativeTime(item.waitingSince)}
-                </p>
-              </div>
-              <Button
-                variant="outline"
-                size="sm"
-                onClick={() => navigate({ to: '/inbox' })}
-              >
-                Answer
-              </Button>
-            </Card>
-          )
-        })}
-      </div>
-    </div>
-  )
-}
diff --git a/apps/web/src/routes/hq.test.tsx b/apps/web/src/routes/hq.test.tsx
index 066cd0d..c9f3ae2 100644
--- a/apps/web/src/routes/hq.test.tsx
+++ b/apps/web/src/routes/hq.test.tsx
@@ -4,9 +4,24 @@ import { render, screen, fireEvent } from '@testing-library/react'
 import { vi, describe, it, expect, beforeEach } from 'vitest'
 
 const mockUseQuery = vi.hoisted(() => vi.fn())
+const mockListWaitingAgentsQuery = vi.hoisted(() => vi.fn())
+const mockListMessagesQuery = vi.hoisted(() => vi.fn())
+const mockGetAgentQuestionsQuery = vi.hoisted(() => vi.fn())
+const mockResumeAgentMutation = vi.hoisted(() => vi.fn())
+const mockStopAgentMutation = vi.hoisted(() => vi.fn())
+const mockRespondToMessageMutation = vi.hoisted(() => vi.fn())
+const mockUseUtils = vi.hoisted(() => vi.fn())
+
 vi.mock('@/lib/trpc', () => ({
   trpc: {
     getHeadquartersDashboard: { useQuery: mockUseQuery },
+    listWaitingAgents: { useQuery: mockListWaitingAgentsQuery },
+    listMessages: { useQuery: mockListMessagesQuery },
+    getAgentQuestions: { useQuery: mockGetAgentQuestionsQuery },
+    resumeAgent: { useMutation: mockResumeAgentMutation },
+    stopAgent: { useMutation: mockStopAgentMutation },
+    respondToMessage: { useMutation: mockRespondToMessageMutation },
+    useUtils: mockUseUtils,
   },
 }))
 
@@ -15,8 +30,33 @@ vi.mock('@/hooks', () => ({
   LiveUpdateRule: undefined,
 }))
 
-vi.mock('@/components/hq/HQWaitingForInputSection', () => ({
-  HQWaitingForInputSection: ({ items }: any) => <div data-testid="waiting">{items.length}</div>,
+vi.mock('@/components/InboxList', () => ({
+  InboxList: ({ agents, selectedAgentId, onSelectAgent }: any) => (
+    <div data-testid="inbox-list">
+      {agents.map((a: any) => (
+        <button
+          key={a.id}
+          data-testid={`agent-${a.id}`}
+          aria-selected={selectedAgentId === a.id}
+          onClick={() => onSelectAgent(a.id)}
+        >
+          {a.name}
+        </button>
+      ))}
+    </div>
+  ),
+}))
+
+vi.mock('@/components/InboxDetailPanel', () => ({
+  InboxDetailPanel: ({ agent, onSubmitAnswers, onDismissQuestions, onDismissMessage, onBack }: any) => (
+    <div data-testid="inbox-detail">
+      <span data-testid="selected-agent-name">{agent.name}</span>
+      <button onClick={() => onSubmitAnswers({ q1: 'answer' })}>Submit</button>
+      <button onClick={onDismissQuestions}>Dismiss Questions</button>
+      <button onClick={onDismissMessage}>Dismiss Message</button>
+      <button onClick={onBack}>Back</button>
+    </div>
+  ),
 }))
 
 vi.mock('@/components/hq/HQNeedsReviewSection', () => ({
@@ -56,6 +96,16 @@ const emptyData = {
 describe('HeadquartersPage', () => {
   beforeEach(() => {
     vi.clearAllMocks()
+    mockListWaitingAgentsQuery.mockReturnValue({ data: [], isLoading: false })
+    mockListMessagesQuery.mockReturnValue({ data: [], isLoading: false })
+    mockGetAgentQuestionsQuery.mockReturnValue({ data: null, isLoading: false, isError: false })
+    mockResumeAgentMutation.mockReturnValue({ mutate: vi.fn(), isPending: false, isError: false })
+    mockStopAgentMutation.mockReturnValue({ mutate: vi.fn(), isPending: false, isError: false })
+    mockRespondToMessageMutation.mockReturnValue({ mutate: vi.fn(), isPending: false, isError: false })
+    mockUseUtils.mockReturnValue({
+      listWaitingAgents: { invalidate: vi.fn() },
+      listMessages: { invalidate: vi.fn() },
+    })
   })
 
   it('renders skeleton loading state', () => {
@@ -68,7 +118,7 @@ describe('HeadquartersPage', () => {
     const skeletons = document.querySelectorAll('[class*="skeleton"], [class*="h-16"]')
     expect(skeletons.length).toBeGreaterThan(0)
     // No section components
-    expect(screen.queryByTestId('waiting')).not.toBeInTheDocument()
+    expect(screen.queryByTestId('inbox-list')).not.toBeInTheDocument()
     expect(screen.queryByTestId('needs-review')).not.toBeInTheDocument()
     expect(screen.queryByTestId('needs-approval')).not.toBeInTheDocument()
     expect(screen.queryByTestId('blocked')).not.toBeInTheDocument()
@@ -93,24 +143,25 @@ describe('HeadquartersPage', () => {
     render(<HeadquartersPage />)
 
     expect(screen.getByTestId('empty-state')).toBeInTheDocument()
-    expect(screen.queryByTestId('waiting')).not.toBeInTheDocument()
+    expect(screen.queryByTestId('inbox-list')).not.toBeInTheDocument()
     expect(screen.queryByTestId('needs-review')).not.toBeInTheDocument()
     expect(screen.queryByTestId('needs-approval')).not.toBeInTheDocument()
     expect(screen.queryByTestId('blocked')).not.toBeInTheDocument()
   })
 
-  it('renders WaitingForInput section when items exist', () => {
+  it('renders InboxList when waitingForInput items exist', () => {
     mockUseQuery.mockReturnValue({
       isLoading: false,
       isError: false,
       data: { ...emptyData, waitingForInput: [{ id: '1' }] },
     })
+    mockListWaitingAgentsQuery.mockReturnValue({
+      data: [{ id: 'a1', name: 'Agent 1', status: 'waiting_for_input', taskId: null, updatedAt: new Date() }],
+      isLoading: false,
+    })
     render(<HeadquartersPage />)
 
-    expect(screen.getByTestId('waiting')).toBeInTheDocument()
-    expect(screen.queryByTestId('needs-review')).not.toBeInTheDocument()
-    expect(screen.queryByTestId('needs-approval')).not.toBeInTheDocument()
-    expect(screen.queryByTestId('blocked')).not.toBeInTheDocument()
+    expect(screen.getByTestId('inbox-list')).toBeInTheDocument()
     expect(screen.queryByTestId('empty-state')).not.toBeInTheDocument()
   })
 
@@ -127,9 +178,13 @@ describe('HeadquartersPage', () => {
         blockedPhases: [{ id: '6' }],
       },
     })
+    mockListWaitingAgentsQuery.mockReturnValue({
+      data: [{ id: 'a1', name: 'Agent 1', status: 'waiting_for_input', taskId: null, updatedAt: new Date() }],
+      isLoading: false,
+    })
     render(<HeadquartersPage />)
 
-    expect(screen.getByTestId('waiting')).toBeInTheDocument()
+    expect(screen.getByTestId('inbox-list')).toBeInTheDocument()
     expect(screen.getByTestId('needs-review')).toBeInTheDocument()
     expect(screen.getByTestId('needs-approval')).toBeInTheDocument()
     expect(screen.getByTestId('resolving-conflicts')).toBeInTheDocument()
@@ -160,4 +215,41 @@ describe('HeadquartersPage', () => {
     expect(screen.getByTestId('needs-review')).toBeInTheDocument()
     expect(screen.queryByTestId('empty-state')).not.toBeInTheDocument()
   })
+
+  it('shows InboxDetailPanel when an agent is selected from InboxList', async () => {
+    mockUseQuery.mockReturnValue({
+      isLoading: false,
+      isError: false,
+      data: { ...emptyData, waitingForInput: [{ id: '1' }] },
+    })
+    mockListWaitingAgentsQuery.mockReturnValue({
+      data: [{ id: 'a1', name: 'Agent 1', status: 'waiting_for_input', taskId: null, updatedAt: new Date() }],
+      isLoading: false,
+    })
+    render(<HeadquartersPage />)
+
+    fireEvent.click(screen.getByTestId('agent-a1'))
+
+    expect(await screen.findByTestId('inbox-detail')).toBeInTheDocument()
+    expect(screen.getByTestId('selected-agent-name')).toHaveTextContent('Agent 1')
+  })
+
+  it('clears selection when Back is clicked in InboxDetailPanel', async () => {
+    mockUseQuery.mockReturnValue({
+      isLoading: false,
+      isError: false,
+      data: { ...emptyData, waitingForInput: [{ id: '1' }] },
+    })
+    mockListWaitingAgentsQuery.mockReturnValue({
+      data: [{ id: 'a1', name: 'Agent 1', status: 'waiting_for_input', taskId: null, updatedAt: new Date() }],
+      isLoading: false,
+    })
+    render(<HeadquartersPage />)
+
+    fireEvent.click(screen.getByTestId('agent-a1'))
+    expect(screen.getByTestId('inbox-detail')).toBeInTheDocument()
+
+    fireEvent.click(screen.getByRole('button', { name: /back/i }))
+    expect(screen.queryByTestId('inbox-detail')).not.toBeInTheDocument()
+  })
 })
diff --git a/apps/web/src/routes/hq.tsx b/apps/web/src/routes/hq.tsx
index d1f881e..368e6bf 100644
--- a/apps/web/src/routes/hq.tsx
+++ b/apps/web/src/routes/hq.tsx
@@ -1,10 +1,13 @@
 import { createFileRoute } from "@tanstack/react-router";
+import { useState } from "react";
 import { motion } from "motion/react";
+import { toast } from "sonner";
 import { trpc } from "@/lib/trpc";
 import { useLiveUpdates, type LiveUpdateRule } from "@/hooks";
 import { Skeleton } from "@/components/ui/skeleton";
 import { Button } from "@/components/ui/button";
-import { HQWaitingForInputSection } from "@/components/hq/HQWaitingForInputSection";
+import { InboxList } from "@/components/InboxList";
+import { InboxDetailPanel } from "@/components/InboxDetailPanel";
 import { HQNeedsReviewSection } from "@/components/hq/HQNeedsReviewSection";
 import { HQNeedsApprovalSection } from "@/components/hq/HQNeedsApprovalSection";
 import { HQResolvingConflictsSection } from "@/components/hq/HQResolvingConflictsSection";
@@ -19,12 +22,108 @@ const HQ_LIVE_UPDATE_RULES: LiveUpdateRule[] = [
   { prefix: "initiative:", invalidate: ["getHeadquartersDashboard"] },
   { prefix: "phase:", invalidate: ["getHeadquartersDashboard"] },
   { prefix: "agent:", invalidate: ["getHeadquartersDashboard"] },
+  { prefix: "agent:", invalidate: ["listWaitingAgents", "listMessages"] },
 ];
 
 export function HeadquartersPage() {
   useLiveUpdates(HQ_LIVE_UPDATE_RULES);
   const query = trpc.getHeadquartersDashboard.useQuery();
 
+  const [selectedAgentId, setSelectedAgentId] = useState<string | null>(null);
+
+  const utils = trpc.useUtils();
+  const agentsQuery = trpc.listWaitingAgents.useQuery();
+  const messagesQuery = trpc.listMessages.useQuery({});
+  const questionsQuery = trpc.getAgentQuestions.useQuery(
+    { id: selectedAgentId! },
+    { enabled: !!selectedAgentId }
+  );
+
+  const resumeAgentMutation = trpc.resumeAgent.useMutation({
+    onSuccess: () => {
+      setSelectedAgentId(null);
+      toast.success("Answer submitted");
+    },
+    onError: () => {
+      toast.error("Failed to submit answer");
+    },
+  });
+
+  const dismissQuestionsMutation = trpc.stopAgent.useMutation({
+    onSuccess: () => {
+      setSelectedAgentId(null);
+      toast.success("Questions dismissed");
+    },
+    onError: () => {
+      toast.error("Failed to dismiss questions");
+    },
+  });
+
+  const respondToMessageMutation = trpc.respondToMessage.useMutation({
+    onSuccess: () => {
+      setSelectedAgentId(null);
+      toast.success("Response sent");
+    },
+    onError: () => {
+      toast.error("Failed to send response");
+    },
+  });
+
+  const agents = agentsQuery.data ?? [];
+  const messages = messagesQuery.data ?? [];
+  const selectedAgent = selectedAgentId
+    ? agents.find((a) => a.id === selectedAgentId) ?? null
+    : null;
+  const selectedMessage = selectedAgentId
+    ? messages
+        .filter((m) => m.senderId === selectedAgentId)
+        .sort(
+          (a, b) =>
+            new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime()
+        )[0] ?? null
+    : null;
+  const pendingQuestions = questionsQuery.data ?? null;
+
+  function handleRefresh() {
+    void utils.listWaitingAgents.invalidate();
+    void utils.listMessages.invalidate();
+  }
+
+  function handleSubmitAnswers(answers: Record<string, string>) {
+    if (!selectedAgentId) return;
+    resumeAgentMutation.mutate({ id: selectedAgentId, answers });
+  }
+
+  function handleDismissQuestions() {
+    if (!selectedAgentId) return;
+    dismissQuestionsMutation.mutate({ id: selectedAgentId });
+  }
+
+  function handleDismiss() {
+    if (!selectedMessage) return;
+    respondToMessageMutation.mutate({
+      id: selectedMessage.id,
+      response: "Acknowledged",
+    });
+  }
+
+  const serializedAgents = agents.map((a) => ({
+    id: a.id,
+    name: a.name,
+    status: a.status,
+    taskId: a.taskId ?? "",
+    updatedAt: String(a.updatedAt),
+  }));
+
+  const serializedMessages = messages.map((m) => ({
+    id: m.id,
+    senderId: m.senderId,
+    content: m.content,
+    requiresResponse: m.requiresResponse,
+    status: m.status,
+    createdAt: String(m.createdAt),
+  }));
+
   if (query.isLoading) {
     return (
       <motion.div
@@ -97,7 +196,80 @@ export function HeadquartersPage() {
       ) : (
         <div className="space-y-8">
           {data.waitingForInput.length > 0 && (
-            <HQWaitingForInputSection items={data.waitingForInput} />
+            <div className="space-y-3">
+              <h2 className="text-sm font-medium text-muted-foreground uppercase tracking-wide">
+                Waiting for Input
+              </h2>
+              <div className="grid grid-cols-1 gap-6 lg:grid-cols-[1fr_400px]">
+                {/* Left: agent list — hidden on mobile when an agent is selected */}
+                <div className={selectedAgent ? "hidden lg:block" : undefined}>
+                  <InboxList
+                    agents={serializedAgents}
+                    messages={serializedMessages}
+                    selectedAgentId={selectedAgentId}
+                    onSelectAgent={setSelectedAgentId}
+                    onRefresh={handleRefresh}
+                  />
+                </div>
+                {/* Right: detail panel */}
+                {selectedAgent ? (
+                  <InboxDetailPanel
+                    agent={{
+                      id: selectedAgent.id,
+                      name: selectedAgent.name,
+                      status: selectedAgent.status,
+                      taskId: selectedAgent.taskId ?? null,
+                      updatedAt: String(selectedAgent.updatedAt),
+                    }}
+                    message={
+                      selectedMessage
+                        ? {
+                            id: selectedMessage.id,
+                            content: selectedMessage.content,
+                            requiresResponse: selectedMessage.requiresResponse,
+                          }
+                        : null
+                    }
+                    questions={
+                      pendingQuestions
+                        ? pendingQuestions.questions.map((q) => ({
+                            id: q.id,
+                            question: q.question,
+                            options: q.options,
+                            multiSelect: q.multiSelect,
+                          }))
+                        : null
+                    }
+                    isLoadingQuestions={questionsQuery.isLoading}
+                    questionsError={
+                      questionsQuery.isError ? questionsQuery.error.message : null
+                    }
+                    onBack={() => setSelectedAgentId(null)}
+                    onSubmitAnswers={handleSubmitAnswers}
+                    onDismissQuestions={handleDismissQuestions}
+                    onDismissMessage={handleDismiss}
+                    isSubmitting={resumeAgentMutation.isPending}
+                    isDismissingQuestions={dismissQuestionsMutation.isPending}
+                    isDismissingMessage={respondToMessageMutation.isPending}
+                    submitError={
+                      resumeAgentMutation.isError
+                        ? resumeAgentMutation.error.message
+                        : null
+                    }
+                    dismissMessageError={
+                      respondToMessageMutation.isError
+                        ? respondToMessageMutation.error.message
+                        : null
+                    }
+                  />
+                ) : (
+                  <div className="hidden flex-col items-center justify-center gap-3 rounded-lg border border-dashed border-border p-8 lg:flex">
+                    <p className="text-sm font-medium text-muted-foreground">No agent selected</p>
+                    <p className="text-xs text-muted-foreground/70">Select an agent from the list to answer their questions</p>
+                  </div>
+                )}
+              </div>
+            </div>
           )}
           {(data.pendingReviewInitiatives.length > 0 ||
             data.pendingReviewPhases.length > 0) && (