A Test for Murder

Dr. Alexander Scofield encounters his friend, retired police captain Waverly Underhill, at a Provincetown art opening. Then they both encounter a murder. The celebrity judge is stabbed in the back upstairs. Downstairs, there are seventy or eighty guests, one of whom must have done it.

Captain Underhill takes charge and quickly devises a simple but ingenious test that will force the killer to reveal himself.