Ex-con Johnny (Stanley Baker) used his time in prison wisely - to plan the biggest robbery of his career. The robbery goes smoothly and Johnny goes to bury the money in a field until the heat is off, as agreed with friend and racketeer Mike Carter (Sam Wanamaker) and the rest of the gang. In a moment of weakness, Johnny pockets five hundred odd pounds from the haul. Coupled with a tip-off from his ex-girlfriend (Jill Bennett) this proves to be his undoing and Johnny is soon back in prison. The rest of the gang try in vain to get the location of the money out of him without success until Mike hits upon the idea of a break-out using Johnny's new love Suzanne (Margit Saad) as bait.