The war ended, the tide rolled back. Left behind were countless tragedies, and not a few mysteries.
The First Lord referred to *this* mystery as 'A jester to the Court of Mars' in a letter to his son, and most of the high command referred to it as Object C, when they referred to it at all. It was found in the desert, at some sort of research facility. The documentation was never good, and both the war and the circumstances of this discovery clouded things further. It had started life as a heavy cargo tractor of the sort converted to artillery duty in large numbers some years ago, but had been fitted with a novel weapon system. The nature of this system has been a source of discreet research and speculation since the end of the conflict, but to no productive end.
It would seem to fire some sort of liquid, though a plasma based system had been theorized at first. Tantalizingly incomplete, a number of design features and a novel use of materials suggested that it was based on some sort of rediscovered Founder technology, though this was impossible to prove. Indeed, when the base was searched for documentation, not only was none found but it was discovered to be not just deserted but devoid of all life (down to the bacterial level) and bereft of all organic matter. A lengthy investigation yielded nothing, but was the subject on intense speculation by all involved. Evidence of anything from an as of yet unclassified apex predator to interdimensional travel was rumored, but never materialized.
Currently Object C is in storage at Base South, awaiting restoration.