1950s British comedy starring Alastair Sim. Seemingly mild-mannered watchmaker Hawkins (Sim) is in fact a skilled assassin. His latest target is leading politician Sir Gregory Upshott (Raymond Huntley), who is due to stay the weekend at the Green Man hotel. However, Hawkins\' well-planned attempts to remove Sir Gregory permanently from public life are frustrated by his neighbour Ann Vincent (Jill Adams) and well-meaning vacuum cleaner salesman William Blake (George Cole).