The San Francisco hospital where the injured Chekov is taken in Star Trek IV: The Voyage Home, and from which Kirk, McCoy and Gillian Taylor rescue him.
Mercy Hospital is a twentieth-century hospital in the Mission District of San Francisco, seen in Star Trek IV: The Voyage Home. Pavel Chekov is taken there under guard after he is badly hurt in a fall while escaping from the aircraft carrier Enterprise, where he and Uhura had been collecting photons from its nuclear reactor.
Kirk, McCoy and Gillian Taylor get in dressed as medical staff. McCoy is appalled by what he regards as medieval medicine. He hands a tablet to an elderly woman on dialysis, who is soon telling everyone that she has grown a new kidney.
In the operating theatre the three lock the surgeons in a side room, and McCoy repairs Chekov's head injury with his own instruments. They wheel him out past the police and are beamed away from a lift.