Wing Commander Tim Mason (Dirk Bogarde) runs a squadron of Avro Lancasters based in England. He is nearing the end of his third tour of operations, meaning that he has flown nearly 90 missions over Germany. Having twice volunteered to continue operational flying, Mason is keen to make it a round 90 "ops", but just as he is nearing the end of his tour he receives orders banning him from further flying. Meanwhile, losses are mounting and several raids are being seen as failures, so that some of the members of his crews, Brown (Bill Kerr) and "The Brat" Greeno (Bryan Forbes) among them, are thinking that there must be a "jinx" at work. Soon afterwards, "The Brat" is caught sending unauthorised telegrams off the station. These turn out to be written to his wife, Pam (Anne Leon), rather than anything more sinister; however, Mason reprimands Greeno for the lapse in security. A few days later, Greeno's aircraft fails to return from a raid and Mason agrees to meet Pam, who has asked to see him.