Este é Mundo Zero por Jason M. Hough.
Esta revisão menciona o sistema de contagem de garrafas de cerveja
This will be the most interesting mission you’ll ever forget.
These words are spoken to assassin Peter Caswell by his handler, Monique Pendleton, as he sets off on the main story arc of ZERO WORLD. Peter is good at his job. At least he thinks he is. He believes he has to be since he continually gets work from his employer, the Archon Corporation. But in this futuristic world, once he completes his mission and eliminates his targets, his memory is wiped. He remembers nothing about what he has done or who he has destroyed. He has secretly devised a count system, employing bottles of beer that he turns so that his re-awoken self knows how many souls he took before the reset, and he recites lines from a Queensryche song to keep himself centered as his memory is erased.
