Originally Aired: July 9, 1957

A Case For Doctor Morelle #12, "Poisoned Air," Doctor Morelle and his secretary Miss Frayle are invited by Professor Hugo Russell to witness a demonstration of his new poisonous gas, designed to kill insect pests. The professor also mentions his upcoming wedding to his secretary, Miss Bella Goodwin, though his legendary absent-mindedness raises questions about whether he'll even remember to attend his own ceremony. When they arrive at the laboratory the next morning, tension crackles beneath the surface. The professor's assistant, the handsome Kurt Emmanuel from Vienna, harbors deep feelings for Bella and attempts to convince her to call off the wedding. Meanwhile, the dangerous gas they've been developing proves as lethal as promised, capable of causing sudden death with just a whiff. As romantic entanglements collide with deadly scientific work, Doctor Morelle finds himself drawn into a case where poisoned emotions may prove just as dangerous as poisoned air.