It had been cut from the kerchief as though by a razor-edge; a few threads ran from it--down toward the base of the slab; ran on to the base of the grey rock and--under it! "The grey rock was a door! And it had opened and Thora had passed through it! "I think that for the next few minutes we all were a little insane.
We beat upon that portal with our hands, with stones and sticks.

At last reason came back to us.
"Goodwin, during the next two hours we tried every way in our power to force entrance through the slab.

The rock resisted our drills.

We tried explosions at the base with charges covered by rock.

They made not the slightest impression on the surface, expending their force, of course, upon the slighter resistance of their coverings.
"Afternoon found us hopeless.