The Great Toonolian Marshes — one of the most feared places in Barsoom with 1800 miles of marsh land infested with exotic and dangerous creatures.

Dejah Thoris, along with her new pilot Kantos Kan, ventures into this foreboding region on an expeditionary mission to find desperately needed minerals. While exploring, Dejah is possessed by "The Boora Witch," an ancient, demonic creature.

Unknown to anyone, The Witch takes control of Dejah and starts spinning a web that could destroy Helium once and for all!

Dejah has overcome many enemies, but can she overcome the enemy within?

This volume also features the stand-alone story of Dejah's journey into the Kaolian Forest and her encounter
with the dreaded giant insects known as the Sith!