Again they retreated, and as the next wave dropped, they expended their energy on nothing but the bald surface of Mephisto. The solid ice of Mephisto boiled into great clouds of vapor and liquid water ran across Mephisto's face for the first time. The vapor clouded operations--for both. One sub-ship scraped Mephisto--broke the barrier, and slid through a crashing pile of accumulating rubble to a destructive stop. And on one upthrust plate, torn and almost obliterated, was the device of the Martian Space Guard! "Martian!" breathed Guy. "Right!" agreed Ben. "Check that wreck!" exploded Guy. "What's running it!" His order was passed: fifty Terran machines raced forward and encircled the smoking ruin; and seven of the planeted constellation ships blasted a pathway back to safety for the carry-alls. The ruined Martian ship was dropped in a clear area, opened by brute force, and through the torn plates streamed a group of cautious Terrans. They emerged immediately. "Martians!" "The devil! They've made a pact!" Maynard looked understandingly at the broken ship. "Naturally," he said sourly. "What would you do?" Williamson looked up and nodded. "Right. Well, does this change anything?" "No--unless it is to apply what we know about fighting Martians to the present situation. We didn't consider this possibility." As Maynard turned to re-enter the _Orionad_, eighteen of Hamilton's raiding horde returned in a screaming landing. Hamilton came out, white-faced, and said, dully: "It was sheer hell--both ways. We got 'em--but they hit us with the book. Sixty percent lost!" "How do you feel?" asked Maynard. "I don't know." "Take your command out again and hit Sector F-67." Hamilton looked up in surprise, and then anger crossed his face. He saluted and said: "Yes sir!" As he turned to go, Maynard called softly: "Hamilton! We're fighting Martians now--they've made a pact!" Hamilton turned, looked at Maynard, and muttered something that Guy could not hear over the roar of battle. Then he returned, and faced Guy. "The stinking, rotten devils--!" His face cleared, and he left. * * * * * Behind the embattled lines of the Mephistans, Martian craft landed. Martian sluggers, Martian power-craft, Martian constellation class super battlecraft. And as they were landing, and getting set for an open battle, the Terran forces lined up behind the thin line that flanked _Orionad_. It was a situation that made Maynard start. For years, no real action had ever been fought between the two forces. Sorties, scrapes, incidents; these had been the sum total of the trouble between the denizens of two worlds. Ream upon ream had been written concerning theoretical battle-plans for war against Mars, and in the Martian pictographs, equally large quantities of ink and paper went into the libraries on how to fight Terra. Guy realized: _Here it is!_