Several deceptively cute burrowing creatures court disaster at a local hospital. At the scene, the team finds evidence of the squirrelly menaces: a Permian Period anomaly, a shaky power supply and large holes in the walls. Cutter, Connor, Abby and Becker must avert calamity by shuttling the critters, called Diictodons, back through the anomaly. While they’re at it, they stretch the bounds of their job descriptions and deliver a woman’s baby.
As if that’s not enough action, the ARC team also faces a bevy of new human adversaries. Dogged journalist Mick Harper is determined to catch a creature and expose the team’s secrets to the world. Meanwhile, at headquarters, Lester, Jenny and Sarah stave off attack as Helen and a small army of “Cleaner Replicas” infiltrate. As the battle plays out, the other team members arrive just in the nick of time.
In the end, Connor brings Rex a couple of new friends: two young Diictodons settle in at his menagerie.