One for the Road follows Jimmy, Paul, Richard and Mark who meet on a rehabilitation course for drink drivers. Jimmy is young, ambitious and desperate to sell his late father's business; Paul has been salesman of the year three times running, however, that was five years ago; Richard is a retired millionaire property developer and Mark is a taxi driver with a weakness for weed and philosophy. Very quickly they realize the course is the networking opportunity of a lifetime as Paul, Mark and Jimmy plot to relieve Richard of some of his wealth...