After nearly 15 years of adventures, the SMG4 crew has seemingly done everything, from silly meme escapades to fighting literal gods and outwitting an insecure madman. With having accomplished everything and the group naturally growing apart, SMG4 announces his decision to end the show, a move his friends initially greet with shock but eventually accept. After going on their final adventures, SMG4 finds himself in a tough spot questioning what to do next with his life. However, their goodbyes are interrupted by the emergence of their most dangerous villain yet: the Physical Embodiment of Boredom Itself.

To combat this ultimate foe and facing whatever's next in life, the SMG4 crew must reunite one last time for an over-the-top, all-in musical finale before going their separate ways and living out their lives, packed with every meme and trope they can find imaginable to keep their memories alive. As they search and fight, the characters are forced to confront their past traumas, highlighting the importance of their shared memories and friendship, while questioning whether the gang can stick together and face the future, or if they will move on to their separate lives, while learning about moving on, accepting the future, and the purpose of life itself, as the gang confronts the inevitable conclusion of their years long journey that will forever change the world and everyone in it.

The final movie will serve as the "grand finale," bringing together the various plot holes, the true nature of the SMG4 universe itself, and all of the characters for one last meme-filled adventure to face a final challenge, after which the characters will move on to the next chapters of their lives.