Dale and Stacey Yorkes, two members of PRIDE, feared that the organization's illegal activities could one day endanger the lives of their children, Gert Yorkes and Molly Hernandez. Therefore, the Yorkeses genetically engineered a small dinosaur, with the intent of protecting them. The Yorkeses kept the existence of the dinosaur a secret, even from Gert and Hernandez, and locked the dinosaur in a secure and sealed environment in the basement of the Yorkes Residence.
Years later, having witnessed the sacrifice of Destiny Gonzalez, the Runaways decided to investigate their parents' activities in order to see whether Gonzalez was still alive. Gert remembered what Hernandez had told her about strange noises coming from the residence's basement and suggested that she and Chase Stein, who had searched through the Stein Mansion with little results, went to the Yorkes Residence to continue their searchings.
Initially, Gert Yorkes and Chase Stein looked into the Yorkes Residence's basement from outside with the X-Ray Specs, but they decided to go into the actual basement for further investigation. Upon discovering a sealed door they were unable to see through, the teenagers heard a strange noise coming from behind the door. Although Yorkes advised Stein against it, he decided to open the door to see what lied beyond.
As soon as Stein opened the door, a massive creature escaped from the room, causing Yorkes and Stein to fall on the ground. They stood back and Stein used the X-Ray Specs to see through the darkness of the basement and see what they were dealing with. Realizing that they had released a dinosaur, they attempted to flee, but the dinosaur stood between them and the door and roared at them.
Yorkes began to have a panic attack, but they realized that the dinosaur actually listened to her when she asked it to step back and leave them alone. However, upon hearing the noise of a car horn, the dinosaur promptly left the basement and the Yorkes Residence, leaving Yorkes and Stein puzzled and still under shock.
Dale and Stacey Yorkes quickly discovered that their dinosaur was missing. They resolved to track it down without telling anybody, which led them to miss an emergency PRIDE meeting. However, their hunt was unsuccessful and they were forced to return to the Yorkes Residence, where they actually found the dinosaur, which had returned home and had nearly attacked Molly Hernandez before being stopped by Gert Yorkes and her telepathic connection with the creature. Dale and Stacey then reluctantly explained the origins of the dinosaur, although their speech was interrupted by the arrival of Tina Minoru.