West and Gordon are after Dr. Theobald Raker (Robert Ellenstein), who has stolen a germ culture which, if it gets too warm, will burst its container and unleash a deadly plague. Raker ends up in a river while trying to escape but when the agents fish his body out they don't find the vial, only an invitation to the house of the very rich and very eccentric Dr. Rufus Kraus (William Schallert). Gordon takes Raker's place, West poses as Raker's bodyguard, and the agents soon find themselves at Kraus' house, playing, along with a group of colorful fellow-guests, various strange games in which the stakes are life and death.
Disguises used by Artie: Drunkyard 
(04:00); Dr Raker ,Criminal Scientist(12:25); Rufus Kraus, Millionaire(42:25)
Tropes present in this episode:
- All Part of the Show: Artie-as-Raker tells Lola that the altercation with Jim was "just a little entertainment between friends."
- Bald of Evil: No-Fun (Lee Kalima), Kraus' bodyguard.
- Dead Person Impersonation: Raker is pronounced dead, so Artie assumes his identity and goes to Kraus' party in his place.
- Deadly Game: Kraus forces his guests to play several of them.
- Death Trap: Jim winds up in the mansion's basement, where No-Fun locks him in a giant cage and plans to cook him to death.
- Destination Defenestration: Jim ends his last fight with No-Fun by knocking the bodyguard out a window.
- Disney Death: Raker falls off a cliff into a river, where he drowns instantly... or so it seems.
- Diving Save: Artie sees a woman about to be shot by a cannon. He runs over and pulls her out of the way just before it fires.
- Eccentric Millionaire: Rufus Kraus, who invites a bunch of people to his house to play ridiculous games with outrageous prizes, then tells them they're all in his will, with the amount they inherit dependent on how many of them remain alive.
- Faking the Dead: Dr. Raker isn't actually dead. The doctor who declared him so was an accomplice.
- Greed: Kraus identifies this as the common flaw in himself and his guests. He keeps them from leaving by showering them with expensive prizes for participating in his games.
- Grumpy Old Man: Rufus Kraus. He was too busy making money to have fun when he was young and has decided to make up for it by bringing together a bunch of people he doesn't like and messing with their minds.
- Masquerade Ball: All of the guests at Kraus' party are required to wear masks.
- Nasty Party: Rufus Kraus' birthday party. There's a good reason he didn't invite people he actually liked (if any such people exist).
- Outlaw Couple: Raker's mole at the party is Charity Witherly (Helen Page Camp), who runs Kraus' games—and is actually Raker's wife.
- Out-of-Character Moment: The heroes do this deliberately when Artie, impersonating Kraus (who has fallen unconscious after overexerting himself), orders his guests to forget the games and go to bed early. As Jim and Artie hoped, this forces the real villain to show his hand. Lampshaded when Charity says Kraus' behavior is unusual, and the disguised Artie says that maybe he's become "a different person" after his brush with death.
- The Plague: Raker has stolen a vial full of a deadly, virulent germ.
- Race Against the Clock: Jim and Artie have to recover the germ culture before it warms up and releases the plague. Lampshaded by frequent shots of the clock on Kraus' music box counting down to disaster.
- Sadist: No-Fun becomes Laughing Mad whenever he does something nasty to Jim.
- Secret Passage: Jim says Kraus' mansion is "honeycombed" with them.
- Shout-Out: Several to Edgar Allan Poe's "The Masque of the Red Death".
- Ten Little Murder Victims: This is the villain's plan at Kraus' party, but Jim and Artie manage to prevent all but one of the murders.
- You No Take Candle: No-Fun's speech pattern.
