The mountains start and the floor begins to shake under the feet.

As we moved on in darkness, the floor began rising.

He sat there feeling sorry for himself until it was gone, then began to pace the floor.

That hollow under the kitchen floor began to trouble him, though.

Then the floor began to lower through the trailer and into the ground below.

Until, that is, the floor on which they stood began to descend.

The floor was beginning to look like the aftermath of a car wreck.

While all watched from safety, the floor began to slide in the direction of the living room.

All at once, the floor under Gail began to curve.

We were so big by then that the floor began to go up and down like a trampoline.