Wendy Watson is an ordinary temp secretary who gets fired when a genetically modified monster goes berserk. This brings her into contact with... the Middleman, a special agent who contracts to take out mad scientists and evil spirits. She tags along on his newest case: looking into monkey business in the Mafia.
Wendy and the Middleman try to stop a Terracotta Warrior from releasing a hail of fire upon the Earth, by stopping him from sacrificing the Emperor's heir. Meanwhile, Lacey is fighting with Wendy over her protest activities.
While the Middleman investigates a diamond theft, Wendy goes to the airport to pick up Sensei Ping, her soon-to-be martial arts trainer. But when Mexican wrestlers kidnap the martial arts master and abduct the Middleman, Wendy must make her way to Yucatan to save them.
A rich woman disappears while shopping and the Middleman and Wendy investigate. The trail leads to a group of gem-eating aliens hiding on Earth, aliens targeted by a mysterious hunter. Meanwhile, the Middleman conducts a series of pop quizzes to see if Wendy is ready to become a Middleman in the future, and Wendy deals with the emotional angst of Ben putting their breakup video on the Internet.
Wendy and the Middleman take on flesh-eating zombies with a taste for... fish?
The duo take on Cindy, the world's biggest and most dangerous fan of a boy-band.
Wendy and the Middleman have to find a cursed tuba that causes anyone who hears it to drown.
A sorority is plagued by ghosts and Wendy has to go undercover to find out what's going on.
When a super villain known as the Candle makes his return, the Middleman must turn to... the former Middleman. Guy Goddard.
An animated puppet holds the key to a mass resurrection of vampires across the Earth.
When Ida is infested with alien nanobots and turns (more) evil, she tricks Wendy and the Middleman into shutting down the HQ.
The duo take on the evil Palindrome, a super-villain who inadvertently transports Wendy to a parallel universe.