Apple TV is stuck on Airplay

I just finished streaming a video over Airplay from my iPad and my Apple TV is "stuck" on the Airplay "now playing" screen. The Apple TV device is responsive to the remote (volume control shows on screen, the light flashes on the device when I press "menu") however the device does not respond to the menu command. My Apple TV is connected via Ethernet; I have unplugged all cables (power, HDMI, Ethernet) and the Airplay screen display persists. How can I recover the device?