"Quickly, now; the rocking stone—tip it over!" gasped the priest.
Where the tunnel ended was its narrowest point. A man might reach out and touch both walls. On the rock above the entrance beetled what Kalin called the "rocking stone." It was an enormous boulder, the fang of some glacial jaw in the primeval, or a fragment spat from the maw of the volcano. Where it had come to rest, at the very verge of the tunnel entrance, it was balanced. So nice was its adjustment on its natural pedestal that the breath of a strong breeze caused it to sway, or rock gently; the hand of a strong man might increase the oscillation greatly.
"Tip it over!" gasped Kalin, pointing with his hand.
A glance told Polaris his purpose. In the passage swelled the clamor of pursuit. He sprang up the rocks, set his powerful shoulder under the belly of the immense stone, and shoved with all his strength.
Over swayed the stone—farther than it had ever swayed before in all the centuries that it had stood there. The solid rock of its foundation grated and crumbled. Over it swung but not far enough to fall. To the straining man, whole minutes seemed to be passing as the stone hung; then, despite his utmost effort, it shuddered—and swung back!
Polaris turned and set his broad back to the surface of the stone as it oscillated. He waited until its recoil swing was completed, and, as it again inclined toward the fissure, he straightened his doubled legs and put forth all the power in his magnificent muscles.
He heard the roaring of the leaping blood in his ears. He heard the uneasy crumbling of the rock at his feet. He shut his eyes and strained grimly—triumphantly! The resistance ceased, and he threw himself on his side to avoid falling. The huge boulder pitched into the tunnel, grinding and crashing, and settled its weight of tons squarely across the passage.
As it went down, there was a flash of white beneath it, and the body of a tall man shot through the portals that were closing forever, and fell on his face on the slope.
It was Minos the Prince! Outdistancing all his men, he had dashed through the passage, and hurled himself at the daylight not one second too soon to escape being crushed under the fall of the rocking stone. Behind his flying heels it closed down, grimly and solidly, splintering the walls at either side to make way for itself. When it rested on the floor of the crevice it completely filled the entrance. Not a squirrel could have clambered through.