"It must have been difficult to source a Jagd-proofed engine," Lumi observed. "Lowerworld import..?"

That, plus the modification... that can't have been easy. The source itself was still a mystery, usually sealed into a chamber of the engine. Books on the subject suggested the substance was volatile, dangerous even, so it was never released. His mechanic had either done something extremely inadvisable and freed it from the casing, or transferred the source, casing and all, into a smaller engine. Either way, they obviously had a talent for it. That could be useful.