The plane swept on. The airfield passed below it. The co-pilot very cautiously let go of the wheel release, which when pulled should let the wheels fall down from their wells to lock themselves in landing position. He moved from his seat. His lips were pinched and tight. He scrabbled at a metal plate in the flooring. He lifted it and looked down. A moment later he had a flashlight. Joe saw the edge of a mirror. There were two mirrors down there, in fact. One could look through both of them into the wheel well. The co-pilot made quite sure. He stood up, leaving the plate off the opening in the floor. "There's something down in the wheel well," he said in a brittle tone. "It looks to me like a grenade. There's a string tied to it. At a guess, that sandy-haired guy set it up like that saboteur sergeant down in Brazil. Only--it rolled a little. And this one goes off when the wheels go down. I think, too, if we belly-land----Better go around again, huh?" The pilot nodded. "First," he said evenly, "we get word down to the ground about the sandy-haired guy, so they'll get him regardless." He picked up the microphone hanging above and behind him and began to speak coldly into it. The transport plane started to swing in wide, sweeping circles over the desert beyond the airport while the pilot explained that there was a grenade in the nose wheel well, set to explode if the wheel were let down or, undoubtedly, if the ship came in to a belly landing. Joe found himself astonishingly unafraid. But he was filled with a pounding rage. He hated the people who wanted to smash the pilot gyros because they were essential to the Space Platform. He hated them more completely than he had known he could hate anybody. He was so filled with fury that it did not occur to him that in any crash or explosive landing that would ruin the gyros, he would automatically be killed. 3 The pilot made an examination down the floor-plate hole, with a flashlight to see by and two mirrors to show him the contents of a spot he could not possibly reach with any instrument. Joe heard his report, made to the ground by radio. "It's a grenade," he said coldly. "It took time to fix it the way it is. At a guess, the ship was booby-trapped at the time of its last overhaul. But it was arranged that the booby trap had to be set, the trigger cocked, by somebody doing something very simple at a different place and later on. We've been flying with that grenade in the wheel well for two weeks. But it was out of sight. Today, back at the airfield, a sandy-haired man reached up and pulled a string he knew how to find. That loosened a slipknot. The grenade rolled down to a new position. Now when the wheel goes down the pin is pulled. You can figure things out from that."