What the girl has done, to-night, is clear enough, of course.

She has joined the two chains, and has fastened them to the hasp in the tin case.

She has sunk the case, in the water or in the quicksand.

She has made the loose end of the chain fast to some place under the rocks, known only to herself.

And she will leave the case secure at its anchorage till the present proceedings have come to an end; after which she can privately pull it up again out of its hiding-place, at her own leisure and convenience.