 In "TCRI," destroying the portal with Leatherhead's help, the turtles learn the Kraang's plans for terraforming Earth and that they are also after April.In the aftermath of "Enemy of My Enemy," one of the Kraang ended up in Foot custody as Shredder interrogated it in "Karai's Vendetta" to why its kind are after the Turtles.When a plan to steal mutagen from TCRI goes array in "The Pulverizer Returns," Shredder decides to form an alliance with the Kraang.