Iapetus Shift

Constant shape-shifting has damaged Olan's DNA so much that he's become dependent on expensive medicine--medicine he can only afford by continued work as a deadly assassin--which requires even more shape-shifting.

Now Olan has finally saved enough money to buy the cure, just one more kill is all he needs. But before he can get out of the business, it all goes wrong and he's forced into a different kind of job--kidnap a super-genius from a secret government facility on Mars, and transport her to a hidden base on Saturn's moon, Iapetus--by any means necessary...