The Rat King is back, more formidable than ever! Taking advantage of the chaos left by the Triceraton invasion, different forces are gathering and worrying power games are setting up to make a low hand on New York. While Turtles try to protect the city from this new threat, he is an Immortal who cares about power or victory and only wants to sow chaos... Will the rat king! Will the Splinter sons manage to stop him before the unnamed happens?