Informed by Buxton that the 'other side' are plotting to kill the Commander, Briggs goes undercover as a restaurant waiter and ends up saving the Commander's life - but nor before he lands himself, and gun, in the soup.

Having tracked to a heliport two Russian agents suspected of organising escape routes to Moscow for agents on the run, Briggs accidentally switches on the airport's Tannoy system - and broadcast his plans to capture them.

Suspecting that Edwards, a clerk in the Documents Section, is responsible for betraying the department's agents to the enemy, Briggs exposed a network of traitors - by mistakenly arresting two 'innocent' men.