An unusual UnderWorld Creature named Phelphor is found frozen inside Ice Pillar by UnderWorlders. Sarah and Kaz scan him. With him being taken to Chaor's castle, Peyton and Kaz head there while Sarah tries Phelphor in the Drome. During the match, Tom nearly codes Sarah, until she discovers Phelphor has an aquatic form and abilities that hypnotize Tom and cause him to code himself. In his castle, Chaor, Agitos, and Takinom are amazed by Phelphor's tale of a lost tribe called M’arrillians and their discovery of the Cothica, Perim's greatest treasure, which they hold behind the Doors of the Deep Mines. Chaor states they will discuss opening the Doors to retrieve the Cothica and dismisses Phelphor. Kaz and Peyton must port out before they can scan to evade Spyder. Phelphor uses his mind control to have Khybon contact Lord Van Bloot so he can unlock the Doors. He also tries to control Chaor, but it fails, though he controls Chaor's guards, which forces him to flee. Chaor recovers and learns Lord Van Bloot is leading his army to the Doors. Chaor and Lord Van Bloot's armies fight, with Chaor going after Phelphor. Phelphor mind controls the guards into opening the Doors of the Deep Mines first, letting out a flood of murky brown water that washes away everything in its path. Tom, Kaz, Peyton and Sarah scan the door as it opens but are forced to port to keep from being washed away. Thus the lost tribe and Perim's forgotten enemies, the M'arrillians, are freed.
