Major Tom Cadnam is taking part in an exercise against an old rival who he later discovers has been having an affair with his wife whilst he's been in Northern Ireland.

In a fit of jealous rage, Fusilier Dave Tucker attacks an NCO and is court-martialled. Will he be discharged from the army, the only family he knows? Tucker's defending officer, Lieutenant Nick Pasco is forced to choose between the army and the woman he loves.