West and Gordon are after Dr. Raker, 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. Gordon takes Raker's place, West poses as 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.
Tropes present in this episode:
- Dead Person Impersonation: Raker is pronounced dead so Artie assumes his identity and goes to Kraus' party in his place.
- 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.
- 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).
- The Plague: Raker has stolen a vial full of a deadly, virulent germ.
- Shout-Out: Several to Edgar Allen 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.