Spencer Tracy plays an American priest tending to the natives of a South Sea island. A plane carrying three convicts -- Harry (Frank Sinatra), Marcel Gregoire Aslan and Charlie Bernie Hamilton) -- lands on the island; Father Doonan (Tracy) manages to enlist their (reluctant) aid in working at a children's hospital. When the island falls victim to a series of earthquakes, Father Doonan and the convicts work together to evacuate the hospital staff and the children. Harry, the least cooperative of the prisoners, becomes a hero during a volcanic eruption by going back to rescue the priest, who with convict Charlie has been holding a bridge in order to allow the others to escape. Father Doonan and the two convicts are killed, but all the children are rescued. Blighted by bad special effects and ponderous direction, Devil at Four O'Clock is less interesting than the behind-the-scenes rumors concerning the friction between Spencer Tracy and Frank Sinatra.