347 Section cooperates with the Royal Navy to deal with a bomb that has a 17-second fuse. Ash decides to ask Susan to marry him.

The Germans have been dropping a new butterfly bomb that are proving difficult to defuse. 347 Section is one of a number of units called to a small English village to deal with them.

The Company packs up and moves to the coast where they are to clear the beaches of dozens of British mines laid in preparation for a German invasion.

Ash convalesces after a near-fatal accident while defusing a mine. With his mobility severely impaired, he is to be reassigned to light duties away from the bomb disposal unit.