The upper caverns were sealed off, but the seal had one weak spot, and that was the guard on the “night” shift. Aton didn’t know what they had to promise him, but Bossman’s given word was good, and the man would be secure for life. He had only to let down the rope and stand aside.

Slowly, slowly, the heavy slab crunched over. The dark hole lightened invitingly, a green glow from the far side, the doorway to success. No face appeared. No sound came from above except for the too-loud scraping of the stone.

A pause; then the rope appeared, spinning out from its coil, swinging free of its basket and undulating as it came. The ragged end dropped just clear of the floor and hung in limp invitation.

Bossman gave a grunt of satisfaction. The selected invasion squad moved to the center, Aton second in the line. The most important thing here was the ability to climb swiftly and silently, with strength left over for immediate combat, if necessary.

The first man, short and game in the legs but with arms of immense power, stepped up and jerked the rope. It gave slightly, but held; it was anchored. Like a tug on a teenage braid, Aton thought.

The man took hold and skillfully hauled himself into the air. Aton saw Bossman watching the operation closely, shaking his head. Are you worried, Krell farmer? he thought. You also remember Tally’s intelligence?

The man climbed swiftly to the top, hoisting himself with both hands and hooking a leg in a bend of rope for occasional pauses. He caught the edge of the hole with his hands and flexed the muscles, raising head and shoulders above it. Aton held the rope, making no motion to follow yet.

A muffled cry came from above. The high legs kicked; the man struggled and lost his grip just as he seemed about to complete his climb. He slid down, back through the hole, and fell heavily to the floor below.

Bossman lifted him immediately, but it did not matter. His throat had been neatly slit.

The rope slackened. A second body fell.

It was the softened guard. The rope had been knotted around his neck. He had served as the anchor, and the climbing weight of the first invader had throttled the traitor.

The revolt had come as no surprise to Tally.