In 1942 A. T. S. (Auxiliary Territorial Service) Pvt. Betty Brown is among the many women assigned to a remote Ack-Ack gunsight on the British coast. The post's commanding officer, Major Pym, does not know that camp casanova Lieut. Gordon "Killer" Brown is Betty's husband. Pym suspects Lieutenant Brown of having an affair with man-chasing Pvt. Marge White, whereupon he suggests that Gordon go on leave to visit his wife. Gordon is unable to reveal that his wife is stationed at the post, and he goes home to London, followed by Marge and an extremely suspicious Betty. In London Major Pym discovers the three in the Brown flat, and the trio return ignominiously to camp. There they learn that the brigadier is making a spot inspection. A series of misadventures ensues, but all ends well when the A. T. S. shoot down an enemy airplane and capture the pilot.