Ambulance 534 is a fictional vehicle featured in the Halloween film series. It is part of the original series of movies and appeared in the beginning of Halloween 4: The Return of Michael Myers in 1988.
Ambulance 534 was a medical services and transport vehicle utilized by the staff of Smith's Grove Sanitarium in Warren County, Illinois. In 1988, a crew of attendants drove the ambulance to Ridgemont Federal Sanitarium for the transfer of a patient named Michael Myers. Myers was a burn victim and had lied comatose for ten years - ever since he committed several murders in the town of Haddonfield and caused a massacre at Haddonfield Memorial Hospital.
The attendants that came to Ridgemont to pick Myers up were J. Black and L. Evans. They transferred Myers out of the sanitarium and loaded him into the back of the ambulance. As the two attendees talked, one of them mentioned Michael's young niece, Jamie Lloyd - a relative that he had no previous knowledge of. Fueled by a desire to track her down, Michael awakened from his state and attacked the attendants. He was particularly brutal to J. Black, slamming his head multiple times against the interior panel of the vehicle and pushing his thumb into his forehead. The ambulance overturned at Mill Creek.