This final film of Raymond Burr finds Burr as Perry Mason defending a soap opera star, Genie Francis, who is accused of murdering her arrogant co-star who was having her character put into a coma and effectively out of the show. The kicker is that her contract would have prevented her from seeking work elsewhere. Of course the victim, Sean Kanan was doing these kinds of things any number of others are prime candidates as a potential killer.
The title Perry Mason: The Case of the Killer Kiss stems from how the victim died. Seems as though he was allergic to walnuts so a script calling for him to plant one on Genie Francis was given him and her lipstick given some walnut oil. Then his allergy medicine was spiked with enough to put him into anaphelaptic shock. Effective indeed.
The Case of the Killer Kiss follows the usual Mason formula, but the real story here is that the film was made at all. Knowing that the series rose and fell with him, Burr signed for the season knowing how ill he was, but also knowing that NBC would have to make the rest of the season quota somehow or pay Barbara Hale and William R. Moses in any event. Hence the 'Perry Mason' movies with Paul Sorvino and Hal Holbrook that followed.
A lot of the footage involving Burr was filmed with him seated or in rear projections or behind something he could lean on, all to disguise the pain he must have been enduring in making The Case of the Killer Kiss. But it was completed and gave Hale and Moses some additional work because of the contract.
I always thought that was one of the classiest things I'd ever read about anyone in show business. I wish that The Case of the Killer Kiss was as worthy of Raymond Burr as The Misfits was for Clark Gable or The Shootist for John Wayne. Still, I suppose just doing the character for which he was most known and loved for is in itself a great tribute.