It follows characters Evumeimei Dingzai (nicknamed Evvy) and Rosethorn, former travel companions of Briar Moss, in their journey to the Battle Islands to investigate the death of the local plantlife and an impending volcano eruption.

[2] It was Pierce's suggestion that she write an original novel for Full Cast Audio, and when she first heard young actress Grace Kelly (actual name) read the part of Evvy during rehearsals for Street Magic, the author decided to recast what she had already written from third to first person so that Kelly could actually narrate the recording.

Bruce Coville, publisher of Full Cast Audio, served as editor for the text, and Pierce herself directed the recording.

[3] Evvy sulks about being aboard a ship to the Battle Islands; she is only there because she used her stone magic to damage some rich boys studying at Winding Circle for bothering her friends, and the alternative punishment was house arrest at Discipline Cottage.

Protective of Rosethorn because they survived the war together, Evvy warns the traveling party about feeling the earth move more than once, often preceded or echoed by Luvo.

Rosethorn and Myrrhtide realize that these spirits precede a volcano eruption; the death of the life on the island is consistent with that conclusion, given the poison that Evvy describes as smelling like rotten eggs.

Because Evvy recognizes that if they break out, they will be so powerful that they may destroy the island, Luvo changes the maze to become like a Möbius strip, with no end to give the humans more time to escape.