In 1945, Gary and Phoebe join a concert party in Belgium to entertain the troops, but a sudden a sudden advance by the Germans leaves them stranded behind the lines. Meanwhile, in 1999, Gary thinks Yvonne might be having an affair and recruits Ron to spy on her while he's away.

Yvonne is reading a biography of Noël Coward and when Gary realises it contains a picture of him in the 1940s, he must take drastic action to ensure his time travelling isn't exposed in the 1990s. Meanwhile, Ron accidentally books a singles holiday with amorous old ladies, and a recently discovered Noël Coward play, Gary & Phoebe, catches Yvonne's eye.