"Terrain looks smooth enough, but we'll fly over and decide whether we want a short landing or a vertical touchdown," Heineman said.

Lanier banked the aircraft and circled around a well, then flew over the cupola at about fifty meters, slowing by angling the props up. Heineman peered at the prospective landing sights and signaled thumbs-up. "Short roll; it's smooth sand down there."

Lanier brought the V/STOL down on the corridor floor at fifty kilometers an hour, gently and easily, nose pointed at the dimple and cupola of the well. He then reduced the pitch on the props and taxied, nose bobbing, to the edge of the dimple, pivoting the plane until it was tangent to the well's outer circle. The engines' roar dropped rapidly to silence.

"Bravo," Heineman said.

"God, that was great," Lanier said. "I haven't flow in six years. . . and I've never flown like that. Jesus, you look at the ground and it seems like you're always going to fly right into it."

"If you two flyboys will give us a hand," Carrolson interrupted, "we'll get out work done faster."

Carrolson took photographs and Farley made instrument readings as they skirted the dimple. The well was open—that much was obvious even from a distance. Ten or eleven meters from the floating cupola was a platform cradling two irregular red-and-black-checked spheres, each three meters in diameter and sporting a pair of waldos front and back.

They descended the slope of the dimple and inspected the platform. Heineman climbed a ladder built into one side of the platform and walked along a scaffold passing above the checked spheres. "Spacesuits," he said. "Tough ones, too."

"Here's a message," Farley called out. She pointed to a bronze-colored plaque mounted on a pedestal near the mouth of the well. The alphabet was Latinesque, with discernible A's, G's and E's, but none of them could decipher the words. "It's not Greek, and it's not Cyrillic," Carrolson said. "It must be Stoner. Some new language." She photographed it from three sides and beneath.

"I never encountered anything like it in the libraries," Lanier said. He stepped beyond the plaque and felt a sudden, molasses-like resistance around the lip of the well.

"WARNING," a deep, forbidding masculine voice announced out of nowhere. "WARNING to be heeded by speakers of twentieth-century English. Do not attempt to enter any gate in this region without proper environmental protection. Conditions of high gravitation and corrosive atmosphere prevail beyond the gate entrance. Suits are provided for your protection. WARNING."

Carrolson touched the plaque and whistled. "Look," she said. The letters of the plaque had reformed into Roman alphabet English and repeated what the voice had said aloud. "Now that's service."

Heineman ran his hands along the upper surface of one of the spheres and found a depression in a black square. He pressed it cautiously; nothing happened.