An eccentric millionairess is lying in a diabetic coma on a hospital bed in an anteroom of the surgical suite of the Dutch Memorial Hospital, which she founded, awaiting the removal of her gall bladder.

The apparent murderer is a member of the surgical staff who was actually seen in the victim's vicinity, but his limp makes him easy to impersonate.

Ellery Queen examines a pair of hospital shoes, one of which has a broken lace that has been mended with surgical tape.

He performs an extended piece of logical deduction based on the shoe, plus such slight clues as the position of a filing cabinet, and creates a list of necessary characteristics of the murderer that narrows the field of suspects down to a single surprising possibility.

"In spite of great length and unnecessary imitation of Van Dine, a well-reasoned solution of an attractive problem.