Orpheus Rising (2017) online

A chance encounter brings Rachel and Ash together. They fall in love... truly, madly, deeply, completely. Ash is well rounded, compassionate, and a professional killer. Rachel, vivacious, creative, and stubborn, an account manager for a design agency. Ash shares many secrets as they tumble into new a new life together, intending to put his work behind him. When he discovers he's not permitted to quit, he finds himself torn between Rachel's love and the work he must do. The two worlds tear him, and their relationship apart