Grell and Colletta start to bring Travis Morgan's quest for his son towards a conclusion in Warlord 19 (March 1979).
Morgan and Tara are zipping along in flyers they took from the moonship, but are being watched by Deimos. Ashiya is with him, and tending to young Joshua Morgan. We learn that Deimos' body is degenerating, and he needs to consume a potion of some kind in order to maintain his life. Deimos causes a storm that makes Morgan and Tara crash.
The pair wind up in the hands of some roving horse riding raiders, much like cossacks or Dothraki. Tara cuts the hand off of one, and Morgan kills a few as well, but they still wind up captured, and thrown into a bear pit.
Machiste and Mariah Romanova appear out of nowhere to rescue them. It turns out these two are the leaders of the quasi-cossacks. We had not seen either of them since the issue in which Morgan returned to Shamballah, which increases my suspicion that the issue following that was meant to have scenes in which we saw them depart the city, scenes cut because of the DC Implosion and reduction in page count. As the story ends we see that Deimos intentionally brought the four together, though why is not clear.