7th in the Platform Eight series of short stories:

When Amy Cordova’s grief over her lover is interrupted by an old acquaintance with a desperate mission, she must pull herself together long enough to strike at the very heart of darkness: the slaver fortress.

The only way in is to become the monster she’d slain, but even from beyond the grave, Gunnar Quinn is a tenacious foe that won’t let go once he has his victim…