Ep 1. Mac and Dennis: Manhunters

In It's Always Sunny In Philadelphia season 4 episode 1, titled "Mac and Dennis: Manhunters," the two best friends and co-owners of Paddy's Pub, Mac and Dennis, have a wild adventure as they set out to catch a thief who has stolen their friend Charlie's (played by Charlie Day) precious bike.

The episode begins with Charlie showing Mac and Dennis his bike, which he just fixed up and is now his prized possession. However, they are interrupted by Dee (played by Kaitlin Olson), who informs them that her car has been stolen. This prompts Mac and Dennis to become obsessed with catching the thief and recovering Charlie's bike, as they believe the same person is responsible for both thefts.

They decide to take matters into their own hands and become "manhunters," dressing up in tactical gear and using walkie-talkies to communicate with each other as they scour the streets for any sign of the thief. Along the way, they interact with various characters, including a homeless man played by Danny DeVito (who also stars as Frank, the other co-owner of Paddy's Pub), and they even break into a house in their pursuit of the thief.

Meanwhile, Charlie is dealing with his own drama as he becomes increasingly paranoid and delusional over the loss of his bike. He imagines himself as a superhero, embarking on his own mission to track down the thief and save the day.

The episode is filled with hilarious moments, such as Mac and Dennis arguing over who is the "bad cop" and who is the "good cop" during their investigation, and Charlie's over-the-top antics as he dons a full costume and takes to the streets on his own mission.

Overall, "Mac and Dennis: Manhunters" is a classic episode of It's Always Sunny In Philadelphia, showcasing the absurd humor and outrageous antics that the show is known for. Whether you're a long-time fan or new to the series, this episode is sure to entertain and leave you in stitches.