The story concerns Don and his friends (Cyril, Steve and Edwin) who are bus mechanics at the huge London Transport bus overhaul works in Aldenham, Hertfordshire. During a miserably wet British summer lunch break, Don arrives, having persuaded London Transport to lend him and his friends an AEC Regent "RT" double-decker bus. This they convert into a holiday caravan, which they drive across continental Europe, intending to reach the South of France. However, their eventual destination is Athens. On the way, they are joined by a girl trio (Sandy, Angie and Mimsie) and a runaway singer (Barbara), pursued by her mother
