On the evening of 24 April 1940 a Royal Navy submarine departed Rosyth in Scotland bound for Norway on what was codenamed ‘Operation Knife’. On board HMS Truant were seven men described by the vessel’s captain, Lieutenant Commander Christopher Hutchinson, as “a bunch of cutthroats”, armed with plastic explosive and a variety of “ghastly looking” weapons.
The seven were led by a Scots Guards officer, Bryan Mayfield, and included Peter Kemp, a veteran of the Spanish Civil War, and Bill Stirling, a former Guards officer and one of the wealthiest landowners in Scotland.
Fifteen days earlier, on 9 April, Germany had invaded Norway, occupying the capital Oslo as well as Bergen, Trondheim and Narvik. The Norwegians, assisted by a hastily assembled British Expeditionary Force, had offered spirited resistance, and the…