When their master was fully restored to full strength (and upon receiving a massive dose of special mutagen), they were ordered to seek out the Turtles down in the subway sewers. They eventually succeeded in breaking through the steel door, where the Turtles, April, and Karai were hiding. The pair clashed with the Turtles several more times before the death of the Shredder in the fourth season finale, "Owari". Despite the death of their master, Tiger Claw, the new leader of the Foot, pressed them into service once again. After the demodragon Kavaxas (voiced by Mark Hamill) resurrected the Shredder as a shambling corpse, Bebop and Rocksteady abandoned the Foot Clan for good in "End Times", out of an accurate fear that they were in over their heads.