The Spires of Turris

Dr. London Wells, linguist and adventurer, has the unique ability to understand any language in the universe, including the languages left behind by the ancient dead races of the Lost Planets – making him an intergalactic celebrity. But London likes his privacy—and he always works alone. No assistants, no entourage. When he goes on expedition to a Lost Planet, it's just him, the memory of dead aliens, and the resident man-eating fauna. He's a self-sufficient sharp shooter whose insatiable curiosity can stand up to any danger.
Until he breaks his head falling from a cliff. That changes everything.
Now, after a long recovery, London is onto the greatest discovery of his life: a language to prove a connection between the Lost Planets. In order to investigate further, he'll need to travel to an unforgiving alien planet. But he can't go alone. That's his dean's last condition: either he travels with a research assistant, or not at all.
Unfortunately for London, graduate student Chas Chambers is not the only unexpected element on this trip…