diff --git a/src/main/runtime/relay/relay-control-client.test.ts b/src/main/runtime/relay/relay-control-client.test.ts
index e07fa5aa434..2cdeb476a4a 100644
--- a/src/main/runtime/relay/relay-control-client.test.ts
+++ b/src/main/runtime/relay/relay-control-client.test.ts
@@ -117,6 +117,72 @@ describe('RelayControlClient', () => {
     )
   })
 
+  it('rejects a control handshake that never receives a proof response', async () => {
+    const server = new WebSocketServer({ port: 0, perMessageDeflate: false })
+    servers.push(server)
+    await new Promise<void>((resolve) => server.once('listening', resolve))
+    const address = server.address()
+    if (!address || typeof address === 'string') {
+      throw new Error('expected TCP relay test server')
+    }
+    const keypair = nacl.box.keyPair()
+    const client = new RelayControlClient({
+      cellUrl: `http://127.0.0.1:${address.port}`,
+      relayJwt: 'scoped-token',
+      relayHostId: createHash('sha256').update(keypair.publicKey).digest('base64url').slice(0, 16),
+      assignmentEpoch: 1,
+      identity: { userId: 'user-1', profileId: 'profile-1', organizationId: 'org-1' },
+      keypair: {
+        ...keypair,
+        publicKeyB64: Buffer.from(keypair.publicKey).toString('base64')
+      },
+      appVersion: '1.2.3',
+      onConnectionOpen: vi.fn(),
+      onDrain: vi.fn(),
+      onClose: vi.fn(),
+      connectDeadlineMs: 20
+    })
+    clients.push(client)
+
+    await expect(client.connect()).rejects.toThrow('relay_control_connect_timeout')
+  })
+
+  it('settles an opening control immediately when ownership closes', async () => {
+    const server = new WebSocketServer({ port: 0, perMessageDeflate: false })
+    servers.push(server)
+    await new Promise<void>((resolve) => server.once('listening', resolve))
+    const address = server.address()
+    if (!address || typeof address === 'string') {
+      throw new Error('expected TCP relay test server')
+    }
+    const keypair = nacl.box.keyPair()
+    const client = new RelayControlClient({
+      cellUrl: `http://127.0.0.1:${address.port}`,
+      relayJwt: 'scoped-token',
+      relayHostId: createHash('sha256').update(keypair.publicKey).digest('base64url').slice(0, 16),
+      assignmentEpoch: 1,
+      identity: { userId: 'user-1', profileId: 'profile-1', organizationId: 'org-1' },
+      keypair: {
+        ...keypair,
+        publicKeyB64: Buffer.from(keypair.publicKey).toString('base64')
+      },
+      appVersion: '1.2.3',
+      onConnectionOpen: vi.fn(),
+      onDrain: vi.fn(),
+      onClose: vi.fn()
+    })
+    clients.push(client)
+    const accepted = new Promise<void>((resolve) => {
+      server.once('connection', () => resolve())
+    })
+    const connecting = client.connect()
+
+    await accepted
+    client.closeNow()
+
+    await expect(connecting).rejects.toThrow('relay_control_closed')
+  })
+
   it('proves the host key and drives control/data commands without URL credentials', async () => {
     const server = new WebSocketServer({ port: 0, perMessageDeflate: false })
     servers.push(server)
diff --git a/src/main/runtime/relay/relay-control-client.ts b/src/main/runtime/relay/relay-control-client.ts
index 750e59359e3..3602ad1359a 100644
--- a/src/main/runtime/relay/relay-control-client.ts
+++ b/src/main/runtime/relay/relay-control-client.ts
@@ -36,8 +36,11 @@ type RelayControlClientOptions = {
   onDrain: (message: RelayDrainMessage) => void
   onClose: (code: number) => void
   createSocket?: (url: string, relayJwt: string) => WebSocket
+  connectDeadlineMs?: number
 }
 
+const RELAY_CONTROL_CONNECT_DEADLINE_MS = 15_000
+
 function controlWebSocketUrl(cellUrl: string): { origin: string; url: string } {
   const parsed = new URL(cellUrl)
   if (parsed.pathname !== '/' || parsed.search || parsed.hash) {
@@ -64,6 +67,7 @@ export class RelayControlClient {
   private state: RelayControlState = 'idle'
   private connectResolve: ((ack: RelayHostHelloAckMessage) => void) | null = null
   private connectReject: ((error: Error) => void) | null = null
+  private connectTimer: ReturnType<typeof setTimeout> | null = null
 
   constructor(options: RelayControlClientOptions) {
     this.options = options
@@ -102,6 +106,12 @@ export class RelayControlClient {
       }
     })
     socket.once('close', (code) => this.handleClose(code))
+    // Recovery cannot advance while an upgrade/proof promise remains pending forever.
+    this.connectTimer = setTimeout(
+      () => this.expireConnect(),
+      this.options.connectDeadlineMs ?? RELAY_CONTROL_CONNECT_DEADLINE_MS
+    )
+    this.connectTimer.unref()
     return new Promise((resolve, reject) => {
       this.connectResolve = resolve
       this.connectReject = reject
@@ -155,7 +165,12 @@ export class RelayControlClient {
   }
 
   closeNow(): void {
+    const wasConnecting = this.state === 'opening' || this.state === 'proving'
     this.state = 'closed'
+    if (wasConnecting) {
+      this.connectReject?.(new Error('relay_control_closed'))
+      this.clearConnectPromise()
+    }
     this.requests.rejectAll(new Error('relay_control_closed'))
     this.socket?.terminate()
     this.socket = null
@@ -279,7 +294,20 @@ export class RelayControlClient {
     this.options.onClose(code)
   }
 
+  private expireConnect(): void {
+    if (this.state !== 'opening' && this.state !== 'proving') {
+      return
+    }
+    this.connectReject?.(new Error('relay_control_connect_timeout'))
+    this.clearConnectPromise()
+    this.socket?.terminate()
+  }
+
   private clearConnectPromise(): void {
+    if (this.connectTimer) {
+      clearTimeout(this.connectTimer)
+      this.connectTimer = null
+    }
     this.connectResolve = null
     this.connectReject = null
   }
diff --git a/src/main/runtime/relay/relay-http-client.test.ts b/src/main/runtime/relay/relay-http-client.test.ts
index 68e27b157ac..889a830f74a 100644
--- a/src/main/runtime/relay/relay-http-client.test.ts
+++ b/src/main/runtime/relay/relay-http-client.test.ts
@@ -57,6 +57,49 @@ describe('relay HTTP client', () => {
     expect(fetch.mock.calls[0]?.[1]?.headers).toMatchObject({
       authorization: 'Bearer scoped-token'
     })
+    expect(fetch.mock.calls[0]?.[1]?.signal).toBeInstanceOf(AbortSignal)
+  })
+
+  it('aborts a blackholed assignment request so recovery can retry', async () => {
+    const fetch = vi.fn<typeof globalThis.fetch>(
+      async (_url, init) =>
+        await new Promise<Response>((_resolve, reject) => {
+          init?.signal?.addEventListener('abort', () => reject(init.signal?.reason), { once: true })
+        })
+    )
+
+    await expect(
+      requestRelayAssignment({
+        directorUrl: 'https://relay.example',
+        relayToken: 'scoped-token',
+        relayHostId: 'AbCdEf0123_-xyZ9',
+        requestDeadlineMs: 5,
+        fetch
+      })
+    ).rejects.toMatchObject({ name: 'TimeoutError' })
+  })
+
+  it('aborts a blackholed token exchange so recovery can retry', async () => {
+    const keypair = nacl.box.keyPair()
+    const fetch = vi.fn<typeof globalThis.fetch>(
+      async (_url, init) =>
+        await new Promise<Response>((_resolve, reject) => {
+          init?.signal?.addEventListener('abort', () => reject(init.signal?.reason), { once: true })
+        })
+    )
+
+    await expect(
+      exchangeRelayAuthorization({
+        endpoint: 'https://auth.example/v1/desktop/auth/relay-token',
+        accessToken: 'ordinary-access-token',
+        keypair: {
+          ...keypair,
+          publicKeyB64: Buffer.from(keypair.publicKey).toString('base64')
+        },
+        requestDeadlineMs: 5,
+        fetch
+      })
+    ).rejects.toMatchObject({ name: 'TimeoutError' })
   })
 
   it('rejects data-plane supplied non-origin URLs', async () => {
diff --git a/src/main/runtime/relay/relay-http-client.ts b/src/main/runtime/relay/relay-http-client.ts
index 6862f26ce6c..f0133c9496d 100644
--- a/src/main/runtime/relay/relay-http-client.ts
+++ b/src/main/runtime/relay/relay-http-client.ts
@@ -4,6 +4,8 @@ import type { E2EEKeypair } from '../e2ee-keypair'
 import { cancelUnreadResponseBody } from '../../lib/unread-response-body'
 import { readFetchResponseJsonWithinLimit } from '../../lib/fetch-response-body'
 
+const RELAY_HTTP_REQUEST_DEADLINE_MS = 15_000
+
 const RelayTokenResponseSchema = z
   .object({
     relayToken: z
@@ -72,6 +74,7 @@ export async function exchangeRelayAuthorization(input: {
   accessToken: string
   keypair: E2EEKeypair
   fetch?: typeof globalThis.fetch
+  requestDeadlineMs?: number
 }): Promise<RelayAuthorization> {
   const relayHostId = deriveRelayHostId(input.keypair.publicKey)
   const response = await (input.fetch ?? globalThis.fetch)(input.endpoint, {
@@ -80,6 +83,8 @@ export async function exchangeRelayAuthorization(input: {
       authorization: `Bearer ${input.accessToken}`,
       'content-type': 'application/json'
     },
+    // A blackholed request must settle so the coordinator can advance its bounded retry state.
+    signal: AbortSignal.timeout(input.requestDeadlineMs ?? RELAY_HTTP_REQUEST_DEADLINE_MS),
     body: JSON.stringify({ relayHostId, hostPublicKeyB64: input.keypair.publicKeyB64 })
   })
   if (!response.ok) {
@@ -100,6 +105,7 @@ export async function requestRelayAssignment(input: {
   relayToken: string
   relayHostId: string
   fetch?: typeof globalThis.fetch
+  requestDeadlineMs?: number
 }): Promise<RelayAssignment> {
   if (!isAllowedRelayOrigin(input.directorUrl)) {
     throw new RelayHttpError('assignment', 400)
@@ -110,6 +116,7 @@ export async function requestRelayAssignment(input: {
       authorization: `Bearer ${input.relayToken}`,
       'content-type': 'application/json'
     },
+    signal: AbortSignal.timeout(input.requestDeadlineMs ?? RELAY_HTTP_REQUEST_DEADLINE_MS),
     body: JSON.stringify({ v: 1, relayHostId: input.relayHostId })
   })
   if (!response.ok) {