After receiving an ominous message from Esmerelda, Rachel and Sasha Jocklin must protect the Bad Guys from an unknown danger. After a magical mishap lands the Bad Guys in Transylvania, where ghosts, magic, and monsters are real, can the reformed felons handle all the spooks, shrieks, and scares?

On a dark Gotham night, the Crimson Paw makes her escape. Yet as she flees from her failed heist, she finds a certain caped crusader hot on her heels. But strangely, he is here for a different reason.

After years of unsanctioned thievery, The Bad Guys get caught by Spider-man, but they plead for their case, wanting to prove that if given the chance they could become good like everyone else. While unclear on their real motives, Professor Marmalade and Spider-man are ready to help them adapt to the right side of society.

Moe Wolf, reformed Bad Guy, returns home to discover that his best bud, Snake, just committed suicide. Two weeks later, he gets emailed a link to a private Spotify podcast, tracks recorded by Snake himself. Snake's voice tells him that there are thirteen reasons why he decided to end his life. Wolf is one of them. If he listens, he'll find out why.

What if instead of saving an old lady, Mr. Wolf meets a baby that makes him want to go good. Never have there been 5 friends as infamous as The Bad Guys: Mr. Wolf, Mr. Snake, Mrs. Tarantula, Mr. Shark, and Mr. Piranha. When they get caught, they make a deal to be good to avoid prison, but can they be good for the baby?

This takes place before Snake's birthday. A few years after the Bad Guys got their powers from the Particle Accelerator Explosion while robbing a bank, Wolf decides to rob the JL's museum to steal some of its priceless artifacts. Wolf believes doing this will show that they're the greatest criminals in the world, but Snake and the others are having doubts on pulling this off.

In the aftermath of the film's events, Diane finally gets the chance to quietly settle some personal matters. But her day off is interrupted by Interpol's de facto expert on master thieves, who shows up several days early, with a lot of questions, right at Diane's front door...