"A desperate call for help interrupts holiday celebrations at the Bureau of Balance, and sends Taako, Magnus and Merle on a high-stakes mission to find and reclaim a fourth deadly relic: a powerful transmutation stone, hidden somewhere in the depths of a floating arcane laboratory that's home to the Doctors Maureen and Lucas Miller. An unknown menace has seized control of the stone, and is using it to transform the lab into a virulent pink crystal...