When Colwyn reached the bottom, the girl and the light had disappeared. But a swift gust of wind in the passage revealed to him that she had gone out by the back door, and closed it after her. He followed along the passage till he felt the latch of the back door in his hand. The door yielded to the lifting of the latch, and he found himself in the open air.
It was a grey northern night, with a bitter wind driving the sea mist in billows over the marshes, and a waning half moon shining fitfully through the dingy clouds which scudded across a lead-coloured sky. By the light of the moon he saw the figure of the girl, already some distance from the house, swiftly making her way along the reedy canal path which threaded the oozing marshes.
Colwyn was not a stranger to marshlands. He had waded knee-deep from dawn to dusk through Irish bogs after wild geese; he had followed the migratory seafowl of Finland, Russia and Serbia into their Scottish breeding haunts, and he had once tried to keep pace with the sweep of the Bore over the Solway Marshes, but he had never undertaken a task so difficult as following this girl across a Norfolk marshland. The path she trod so unhesitatingly was narrow, and slippery, with the canal on one side and the marshes on the other. In keeping clear of the canal Colwyn frequently found himself slipping into the marshes. His feet and legs speedily became wet and caked with ooze, and once he nearly lost one of his boots, which he had pulled on hurriedly outside the inn, and left unlaced.
But the girl walked straight on with a swift and even gait, treading the narrow path across the morass as securely as though she had been on the high road. Colwyn soon realised that the path they were following was taking them straight across the marshes to the sea. The surging of the waves against the breakwater sounded increasingly loud on his ears, and after a while he saw the breakwater itself rise momentarily out of the darkness like a yellow wall, only to disappear again. But presently it was visible once more, looming out in increasing clearness, with a ghostly glimmering of the grey waters of the North Sea heaving turbulently outside.
As they neared the breakwater the path became drier and firmer, and the light of the moon, falling through a ragged rift in the scurrying clouds, showed a line of sand banks and strips of tussock-land emerging from the marshes as the marshes approached the sea.
The girl kept on with the same resolute pace, until she reached a spot where the canal found its outlet to the sea. There she turned aside and skirted the breakwater wall for a little distance, as if searching for something. The next moment she was scaling the breakwater wall. Colwyn was too far away to intercept her, or reach her if she slipped. He stopped and watched her climb to the top of the wall, and stand there, like a creature of the sea, with the spray leaping hungrily at her slight figure. He saw her take something from the bosom of her dress and cast it into the wild waste of seething waters in front of her. Having done this she turned to descend the breakwater. Colwyn had barely time to leave the path, and take refuge in the shadow of the wall, before she reached the path again and set out to retrace her steps across the lonely marshes.
CHAPTER XI
Colwyn waited on the marshes until the coming of the dawn revealed the breakwater and the sea crashing against it. A brief scrutiny of the white waste of waters, raging endlessly against the barrier, convinced him of the futility of attempting to discover what the innkeeper's daughter had thrown from the breakwater wall an hour before. The sea would retain her secret.