An invisible assassin's crossbow bolt that secretly drains a victim to near-death and hides the killer's identity.
The Dirty Little Phased Bolt is an assassin's crossbow bolt and the weapon of Hekla's betrayal on the Vermillion line. A "phased" item, it is fully invisible — it hides its entry wound, discoverable only by physical touch — and on hit casts Temporary Amnesia and Suffering Bleed, draining the victim to 10% health (a second bolt drops them to 1%). Anyone who then dies is logged as killed by "an alternate source," so the shooter earns no kill credit, no experience, and crucially no player-killer skull.
Amid the ghoul-slaughter, Hekla fires two of these into Katia Grim's train-mounted scoop, mixed among her normal bolts, secretly draining Katia toward death while feigning that the ghouls did it. Only Princess Donut's Prism goggles catch the invisible arrows; Carl gropes them out of Katia's shoulder (one already broken), exposing the murder attempt.
An invisible crossbow bolt that leaves no visible wound; when touched and pulled free, the hole and shaft become briefly visible (the recovered one splintered/broken).
Hekla's deniable assassination weapon, the instrument of her attempt to murder Katia without consequence.
Also appears in books you've already read — spoiler-safe to their endings: