Howard agress to be Al's chauffeur for a stag do he's organising for his old mate Russell - Al went to uni with Russell, who's now a top criminal lawyer and American friend Buck, now a successful psychologist. The three friends become nostalgic until a shock revelation about something that happened between Buck and Russell at uni results in a drunken Buck storming off. Then, Russell makes a nasty comment to Al, who also leaves.
Meanwhile, Buck's wandering along a country path when he slips and falls into a ditch. When Al finds Buck in the ditch he breaks into hysterical laughter until he realises a metal railing has gone straight through Buck's leg. Howard gets Al's medical bag but a drunk Al is in shock and not sure what to do. Howard slaps him; Al always goes on about how good he is, now is the time to prove it!
Al makes a tourniquet with Howard's tie to stop the bleeding and then, although he's got the shakes, manages to give Buck an injection to increase his heart rate. Then Al desperately starts CPR and, after some time, Buck starts breathing again. Later, at the hospital, Al admits Howard saw him at a weak moment, but it's turned out he was the hero today. As Al goes back to sit with Buck, Howard sees just how nervous and shaken up he is.
Also, Heston clashes with Rob when he encounters a postman who claims to have discovered a body.
