In 1915 France, Major Brand commands the 39th Squadron of the Royal Flying Corps. The young airmen go up in bullet-riddled "crates" and the casualty rate is appalling, but Brand can't make the "brass hats" at headquarters see reason. Insubordinate air ace Captain Courtney is another thorn in Brand's side...but finds the smile wiped from his face when he rises to command the squadron himself. Everyone keeps a stiff upper lip.
Drummond has to leave for Morocco on his wedding day with his fiancee and trusted friends to rescue his friend Nielsen who is kidnapped by an international criminal.
Drummond's wedding with Phyllis is interrupted when the inspector guarding their gifts is killed. He tries to trace the killers and uncovers the mystery of diamond counterfeiters.