In the courtyard behind them, Willie’s ground rig rolled out of the whizzer. The rig was a low-slung armored cart. The ceramet armor of its sloped sides would stand up to anything short of a missile, but the courtyard lacked space for a missile to arm itself. Weapon-snouted turrets and bulbous sensor domes sprouted like high-tech mushrooms on the cart’s dorsal surface. As soon as the rig’s rear tires touched the paving, the ramp slid back and the; personnel hatch slammed shut. The whizzer would stay locked until the raiding party returned. Until then, the armored ground rig would stand guard and hold the retreat line.