After an encounter with an unknown element in the sewers of the city, the Rat King finds his ability to control the hearts and minds of rodents is waning. But in its place, he finds the ability to control reptile life, which will make things harder for the Heroes in a Half Shell! Plus, the TMNT are stoked when Professor McGuffin sends them on a expedition to the ocean floor where the heroes are shell-shocked to discover Turtlantis, a subaqueous civilization that reveres turtles! Then, after learning that the Shredder has stolen an indestructible meteorite from TCRI, Donatello discovers an interdimensional signal in the Deep South that he thinks might be connected, and gets some help from the Punk Frogs!

"Originally published as Teenage Mutant Ninja Turtles: Saturday Morning Adventures (2023) issues #1-5"--Title page verso.

The Turtle King /art by Tim Lattie, Jack Lawrence ; inks by Jack Lawrence ; colors by Raul Angulo ; letters by Ed Dukeshire -- Voyage to ... Turtlantis! / art by Dan Schoening ; colors by Luis Antonio Delgado ; letters by Ed Dukeshire -- Swapping pads / art by Dan Schoening ; colors by Luis Antonio Delgado ; letters by Ed Dukeshire.