The Sonic Underground come across ARTT (Artificial Robot Thought Technology), Robotnik's most powerful robot ever, that can think and learn for itself. But ARTT soon learns the power of friendship and switches to the Resistance. This gives a vengeful Sleet the opportunity to finish off ARTT and the hedgehogs before time runs out. (During this episode the Sonic Underground play a song that they played at a night club in the 1st episode)