Enter the Upside Down! Leo, Mikey, Will, Lucas, and Dustin enter the Upside Down to learn more about the Demodogs running around NYC. However, as the Turtles enter new territory, they'll find something familiar. And in Baxter Stockman's lab, Eleven must wrestle control of her mind away from the mad scientist. Luckily, she'll have help in this battle of minds from the Turtle with the most mental restraint: Raphael! Wait, what?