Looking back and evaluating your life's value causes headaches. At least I never had to kill for Queen and Country.

Darkness on His Bones: A James Asher vampire mystery - Barbara Hambly

Aside from Buffy, this is my favorite vampire series.  

 

"Asher drifted again into feverish sleep. A year ago he had warned Ysidro that he would no longer abide or endure the odd partnership – – close enough at times to border on friendship – – that for the past seven years had existed between himself and the vampire. From what felt like an enormous distance he saw himself and Ysidro together by lantern-light in a dream he'd had of African twilight, and reflected that it didn't seem to matter to the vampire what he, James Asher, could abide or endure.

And the past few days had brought home to him that his own commitment to what was right, to the deserts justly due to this pale predator – – wouldn't stand the test of expediency either.

And Ysidro knew it. Had known it from their first meeting.

Had he walked in my dreams and known that of me, before we met? Was that how he chose me as his tool?

He'd come back, a hundred times, from 'abroad,' in the days of his service to the Queen, loathing himself and the things that he had done. Loathing his calm readiness to kill total strangers, his undoubted facility for theft, fraud, lies, and the betrayal of those 'enemy' civilians who'd trusted the man they'd thought he was. Like poisoned magic, the words 'for Queen and country' had always drawn him back. And the knowledge that he was good at what he did.

Thus he recognized that he was apparently perfectly willing to form a partnership with Don Simon Ysidro – – knowing full well what Ysidro was and did – – if those he, James Asher, personally loved were in danger.
He had done far worse, for goals less vital and true.
What does that make me?
He didn't know, and his head hurt too much to think."