He was astonished to see how far the tide had risen in the night.  The line of seaweed and drift marking its highest point was well up the bank.  Now the ebb was foaming past the end of the wharf.  He looked for the lobster car, which should have been floating at its moorings, but could not see it.  Either it was under the wharf or it had been swept away and was gone.  And one of the dories was gone, too.  No, there it was, across the cove, high and dry on the beach.  If so much damage was visible from where he stood, it was probable that a closer examination might show even more.  He reentered the kitchen, took the boathouse key from its nail—­the key to Seth’s wonderful purchase, the spring lock which was to keep out thieves and had so far been of no use except as a trouble-maker—­and started for the wharf.  As he passed the table he picked up the bundle of newspapers and took them with him.  The boathouse was the repository for rubbish, old papers and magazines included, and these might as well be added to the heap.  Atkins had not read this particular lot, but the substitute assistant did not think of this.

The lobster car was not under the wharf.  The ropes which had moored it were broken, and the car was gone.  Splinters and dents in the piles showed where it had banged and thumped in the grasp of the tide before breaking loose.  And, lying flat on the wharf and peering under it, it seemed to him that the piles themselves were a trifle aslant; that the whole wharf had settled down on the outer side.

He rose and was about to go further out for another examination, when his foot struck the pile of papers he had brought with him.  He picked them up, and, unlocking the boathouse door—­it stuck and required considerable effort to open it—­entered the building, tossed the papers on the floor, and turned to go out.  Before he could do so the door swung shut with a bang and a click.

At first he did not realize what the click meant.  Not until he tried to open it did he understand.  The settling of the wharf had thrown the door and its frame out of the perpendicular.  That was why it stuck and opened with such reluctance.  When he opened it, he had, so to speak, pushed it uphill.  Its own weight had swung it back, and the spring lock—­in which he had left the key—­had worked exactly as the circular of directions declared it would do.  He was a prisoner in that boathouse.

Even then he did not fully grasp the situation.  He uttered an exclamation of impatience and tugged at the door; but it was heavy, jammed tight in its frame, and the lock was new and strong.  He might as well have tried to pull up the wharf.