Gibbie would fain have got in, to try whether the place was good for sleep; but he found both halves fast.

In the lower half, however, he spied a hole, which, though not so large, reminded him of the entrance to the kennel of his dog host; but alas! it had a door too, shut from the inside.

There might be some way of opening it.

He felt about, and soon discovered that it was a sliding valve, which he could push to either side.

It was, in fact, the cat's door, specially constructed for her convenience of entrance and exit.