Stuart had forgotten to buckle his safety straps. He just had time to grab a stanchion when the violent acceleration tripled his weight and nearly threw him to the floor. No more than a heartbeat later, there was a muffled boom from outside the ship, and a section of blazing tree went rocketing past the glassite window. After a few seconds' acceleration he felt the ship take on a horizontal component. The pressure eased off. He got up from his hands and knees and adjusted the periscope controls until he got a view of the ground. There was a group of burning trees several kilometers below, sliding rapidly to the east. Several times the scenery shifted rapidly as the ship zigzagged. As he swung the 'scope, Stuart was thunderstruck to discover a hole blasted in the edge of a fin, not four meters away from where he stood. Shreds of charred camouflage netting fluttered in tangled strings. On the intercom, White's voice broke the tense silence. "Gimme that again, slowly, somebody. What happened, anyway?" Gordon answered. "That must have been a tunnel they came out of, right at the edge of the woods. Maybe they use it to get home if hell-cats happen to catch them out on the prairie. That fellow we caught today was probably heading for it, hoping to lose the cats in the woods first." After a moment, he added, "Anyway, they showed up with a heavy weapon and nearly got us. Patrol guessed wrong about its portability, and I guessed wrong about its operation." Stuart commented, "Good thing someone happened to be on duty in the turret, and we were able to take off on such short notice." "_Happened!_" barked the captain. "Mr. Stuart, that's the first rule of _any_ ship landing on territory listed as 'unsafe', and it 'happens' to be Rules Seven through Sixteen of the Patrol Regulations!" Brettner eased the linguist's embarrassment by changing the subject a little. "Did you all see the colossal helpers they had carrying that weapon? Must be what the traders called heffalumps ... I thought the pictures were fakes. Those critters practically did the shooting themselves, and they were talking to the natives! This is some planet--everybody talks to everybody except us!" Gordon spoke again. "White, I want you to rig up a mosaic alarm with controls in the turret, Number One Lock, and control room ... before tonight, if possible. Jury-rig it, just so it goes off when anything larger than a mossback moves near the ship. Get as much range as you can." "That means dismantling the space-probe and comparator, boss. Not enough spare checkerboards to scan three hundred and sixty degrees with a decent vertical coverage. And for stereo-perception, so the thing can discriminate between a nearby leaf and a far-away heffalump--" "All right, do the best you can. Can you hook it up with an infra-red snooper for night work? I don't believe the natives can see infra-red ... I hope. Procyon's a little farther toward the blue than Sol is."