They called it BD2 in the shop—a terse label born of spreadsheets and fault codes. To Marcus it sounded softer, stranger: a pulse, a complaint. Hot injector. Not the fever of combustion, not the ordinary warmth of a fired cylinder, but a specific, localized burn where metal met wiring and timing met tolerance. The car’s dash had whispered the first clue, then the owner’s frown amplified it: rough idles, a hiccup on acceleration, a scent of gasoline like a memory of summer. Mechanics call patterns by names; engines keep their own counsel.