In the atavistic milieu plausibly conjured up by Mayer for his latest thriller (Eyes of the Hammer, Dragon SIM-13), Synbats are synthetic battle forms--expendable, elementally sentient, genetically altered baboons developed for military duties deemed too hazardous or risky for higher-order troops. One dark night, a small group of the lethal man-made beasts escape from Biotech Engineering--an ultrasecret lab in rural Kentucky whose sinister work is generously funded from the Pentagon's so-called black budget. Eager to keep the breakout (and project) under wraps, the Defense Intelligence Agency assigns a crack Green Beret unit--led by Chief Warrant Officer Dave Riley (the protagonist of what now promises to be a durable series)--to round up the renegade Synbats. But since neither DIA operatives nor their coverup-minded superiors have fully briefed the doughty CWO, the fugitive brutes make monkeys of him and his well-equipped A- team, compiling a fearsome body-count (of horses and humans) in the Tennessee woodlands to which they've fled. Armed and dangerous, the runaways eventually hitch a truck ride to Chicago with a couple of unfortunate brothers who'd gone south to take part in the reenactment of a Civil War engagement. Once in the Windy City, the wily simians (who can reproduce themselves in a matter of months) take refuge in the downtown sewer system. The details of how Riley tracks them down and (with help from a comely police lieutenant) ruthlessly keeps a lid on their very existence make for a riveting climax to a taut procedural that cuts to the high-tech chase at every opportunity. Action-packed entertainment--with primate villains that are not, alas, based on paranoid fantasies but on probable results of research programs reported to have been funded by the US government.