The Grunts on the run

"Over the years, the Grunts have made more than a few enemies. But fortunately they're all safely behind bars. Or are they? There's been a prison break-out, and three of them are after REVENGE. It's time for the Grunts to go On the Run ... This last book brings back some familiar faces from the series and solves a couple of mysteries too ..."--Publisher's information.