When Raphael and Michelangelo discover the entrance to a large tunnel in their house, Donatello's newly found crystal starts glowing. The turtles enter the tunnel but are soon confronted by ... Read allWhen Raphael and Michelangelo discover the entrance to a large tunnel in their house, Donatello's newly found crystal starts glowing. The turtles enter the tunnel but are soon confronted by genetically mutated humans.When Raphael and Michelangelo discover the entrance to a large tunnel in their house, Donatello's newly found crystal starts glowing. The turtles enter the tunnel but are soon confronted by genetically mutated humans.