1941, Lt. Ogleby (Ian Carmichael) is the cheerfully inept officer in charge of a searchlight battery codenamed ‘Lionheart’ stationed at a requisitioned cricket ground. His detail is led by officious ‘Thommo’ Tomlinson (Victor Maddern) who tries his best to keep his troops attention on the aircraft-spotting task in hand. He’s joined bymusic-hall cabaret act the McGaffey Brothers; light-fingered Syd McGaffey (Benny Hill) and his brother Eric (Tommy Steele) who gets married then hears his mistress is pregnant. Lovesick ‘Smithy’ Smith (Johnny Briggs) mopes about the station all day daydreaming about his girlfriend until eventually going AWOL to Sheffield. Cockney Roland Kenyon (Harry Locke) appears more interested in cooking for the Catering Corps in a big white hat than shooting down German aircraft. The unit’s father figure is Ted Green (Sydney Tafler), who is mourning the loss of his son in action.