Warlord of Mars: Dejah Thoris #20

Synopsis

Dejah returns to Barsoom to find that Mortus, the leader of a new assassins guild, has been killing the leaders of Helium. Her father refuses to let her go to Zodanga with Gunbor to infiltrate a rival assassins guild but she stows away aboard his ship and reveals herself only when it is too late to turn back. Gunbor and Dejah join the house of Xam Lin and are sent to spy on Mortus' operations.