"If I could slap you on the back by phone, I'd do it. I'm waiting for you with the ship. Hurry." Professor Haven was delighted at the opportunity; the wizened little fellow seemed oblivious to the dangers of the undertaking. They put rifles in the plane, and two forty-fives apiece in their belts. The walled enclosure was visible to the plane from a distance, because of a strange reddish glow that came up from it. The glow enabled the lieutenant to note that a long, flat-roofed building offered a far better opportunity for a landing than did the ground, which was systematically spaced with guards. He shut off his motor several miles away, and managed his landing with marvelous skill and silence. Only the landing-wheels, bumping over the rough places on the roof, made any sound. They waited for thirty minutes in silence, and as no further sounds came from the camp, they crept out of the cockpit and stole along the roof. The guards pacing about below seemed not to have noticed their landing. Ahead of them was a large, square affair like a chimney, with a red glow coming out of it. But, it was not a chimney, for no heat came from it. It might have been a ventilator; in fact as they approached they found that a strong current of air drew _downward_ into it. They could lean over the edge and see a large, bright room immediately below them. It was certainly no crude Roman room. It was a scientific laboratory, crowded with strange and delicate apparatus. Most of it was quite unfamiliar to John in use or nature, despite the fact that he was well posted on modern scientific matters, and could make intelligent guesses about scientific things or equipment even out of his own line. He could make nothing out of the things he saw below. Just beneath them stood a huge Roman officer; the numerous gold insignia on his chest indicated high rank. He stood in front of a glass jar about four feet high, from which numerous cords led to a table full of intricate apparatus. Inside the jar there was something that looked like a piece of seaweed. It was hard, tough, leathery. In the bright light, it might have been a sort of a branching cactus. But it moved about within its jar. It gestured with one of its branches. It pointed at the Roman soldier, and nodded a large, head-like portion. A rapid rattle of words in a foreign tongue came up to them, and Haven, the Latin professor, craned his neck. John recognized a Latin word here and there, but could make out no meaning. Haven later translated what he had heard. The first words he distinguished were those of the big Roman general. "We need fifty more legions of men by morning," he said apologetically. "Why not?" a metallic voice replied. It continued monotonously, with scant intonation. "I'll start them at once and have them ready by daylight." There was a quick gesture of the leathery thing in the jar. Little groups of long, red thorns scattered over it. The general went on.