When his son is killed by an unidentified hit-and-run driver, Felix Lane writes in his diary that he intends to find the man responsible and kill him. But when the man actually is killed, is someone else the killer?

This play is set in the West End of London in the nineteen-thirties. It appears that there are a large number of people who would be glad to see Sir William Anstruther dead. The question is who? Roger Sheringham is determined to find out. Unhappily he has hardly started his investigations when a tragedy, in which an innocent woman dies, takes place.

Advising government on the illegal "high" called Mecron, Rachel Borrowdaile comes to the aid of minister Henry Leggatt who is blackmailed by drug pushers who want old stock.