"Also, under normal circumstances I wouldn't kill any innocent bystanders in order to save others unless the balance were massively skewed the other way, but I will take an extra loop or ten if I manage to kill the big witch but only with more casualties than I feel like accepting, and describing this as 'killing seven billion people a little bit in order to save Vancouver' seems to make it more of a gray area than it really is. What I think of myself as doing is - the memories anybody but me was going to have of that month are gone. And they can only come away from this entire business with one set. My job is to optimize that set so it contains few dead people and little property damage and so I come out the end of it so superlatively competent that I can also then go on to dismantle the evil aliens' humans-as-power-source system."