Beta Testers is a prequel novella in the Big Sigma setting.
It's important to use the right tool for the job... even if that tool hasn't been tested.
Garotte is the sort of covert operative a military sends in to tug at threads until a situation unravels. After a particularly ill-advised assignment causes the situation to escalate, he takes it upon himself to right what's gone wrong before it gets out of control. The task is too big for one soldier, so he seeks out the aide of Jessica "Silo" Winters, a more traditional soldier with whom he shares a complex past.
But a battle can't be fought without weapons, and beggars can't be choosers. Fortunately, Garotte has the name and address of an ex-military contractor, a man called Karter Dee. Unfortunately, Karter's equipment isn't always as reliable—or sane—as one would like.