 The eccentric misanthrope Mr. Oscar Hemmings, who died very old in Community General without friends, left his sizable fortune to six people, including Jesse and Amanda, in the form of a  tontine  legacy which is only inherited by the last survivor, as a deliberate recipe for murder. After a parade of loony applicants, Mark hires at Steves enthusiastic insistence college-graduate Ingrid Thurston as new secretary. An explosion in the bio-lab kills med student Jerry Royce, a tontine member. Jesses dinner date dies from a Bordeaux from his locker, injected with an anti-depression drug which contact with red wine renders poisonous. After Dr. Phillip Zachary is killed by a halter in the gym, and Mr. Leonard Drexel, whose wife Mary needed an expensive operation, dies next, there must be a mysterious seventh person with a motive- now Mark learns the tontine could become invalid after murder charges, thus benefiting a surviving distant relative of Hemmings, notably Priscilla alias Ingrid. Now Jesse has a grave car accident- fortunately faked...