Some TMNT stuff really isn't for little kids.
- April O'Neil (debut)
- Baxter Stockman (debut)
- Donatello (debut)
- Leonardo (debut)
- Old Hob (debut)
- Michelangelo (debut)
- Raphael (debut)
- Hamato Yoshi / Splinter (debut)
- Arnold Jones (debut)
- Casey Jones (debut)
- Chet Allen (debut)
- General Krang (debut)
- Lindsey Baker (debut)
The book opens with Splinter and three of the Turtles—Donatello, Michelangelo, and Leonardo—about to face off against the vicious one-eyed cat mutant Old Hob and his human henchmen. The Turtles trounce the humans, while Splinter takes the feline, felling him in combat. As Old Hob retreats, his words sting the hearts of the Turtles and Splinter as he reminds them of Raphael's absence.
Eighteen months prior, at StockGen Research, Inc., Dr. Chet Allen introduces new intern April O'Neil to the work they do, including the four baby turtles used in research. A large rat appears on the turtles' tank, prompting April to freak out, but Chet explains that he's a part of another experiment and is hard to keep contained.
Meanwhile, StockGen's owner, Baxter Stockman, speaks to his mysterious benefactor, General Krang. Krang is unhappy with Stockman's delay in the situation report of the experiments that he is funding to aid in his war.
Three months later, April has taken a liking to the turtles, but not to the rat, who fellow StockGen employee Lindsey Baker identifies as Splinter, due to the psychotropic drug therapy they are running on him, which splinters his cognition from his instincts. April takes alarm, as she thought StockGen was primarily a corporation for bioengineering meat. Lindsey sloppily excuses herself, leaving Chet to cover for her.
Chet suggests that April name the turtles due to her attachment, but to his surprise, she already has. Her enrollment in a History of Renaissance Art 101 class has prompted her to name them after famous Italian Renaissance artists—the quiet, peaceful one is Leonardo, the studious one is Donatello, the big eater is Michelangelo, and the feisty, solitary turtle is Raphael.
In the present day, a hooded Raphael digs through dumpsters for food. The contents of the pizza box he finds is disappointingly inadequate, and the next dumpster he spelunks contains a "Cowabunga" t-shirt. Before he can continue digging, Raphael is distracted by loud noise—a man beating his son. In anger, Raphael breaks down the door and interrupts the violence.
- This issue shipped with 12 distinctively different covers. Many more different covers were subsequently produced for rereleases and conventions.