Why, we’ve found him ourselves, miles from home, and quite self-possessed and cheerful!’

‘Yes; but this time it’s more serious,’ said the Rat gravely. ‘He’s been missing for some days now, and the Otters have hunted everywhere, high and low, without finding the slightest trace. And they’ve asked every animal, too, for miles around, and no one knows anything about him. Otter’s evidently more anxious than he’ll admit. I got out of him that young Portly hasn’t learnt to swim very well yet, and I can see he’s thinking of the weir. There’s a lot of water coming down still, considering the time of the year, and the place always had a fascination for the child. And then there are — well, traps and things — you know. Otter’s not the fellow to be nervous about any son of his before it’s time. And now he is nervous. When I left, he came out with me — said he wanted some air, and talked about stretching his legs. But I could see it wasn’t that, so I drew him out and pumped him, and got it all from him at last. He was going to spend the night watching by the ford. You know the place where the old ford used to be, in by-gone days before they built the bridge?’

‘I know it well,’ said the Mole. ‘But why should Otter choose to watch there?’

‘Well, it seems that it was there he gave Portly his first swimming-lesson,’ continued the Rat. ‘From that shallow, gravelly spit near the bank. And it was there he used to teach him fishing, and there young Portly caught his first fish, of which he was so very proud. The child loved the spot, and Otter thinks that if he came wandering back from wherever he is — if he is anywhere by this time, poor little chap — he might make for the ford he was so fond of; or if he came across it he’d remember it well, and stop there and play, perhaps. So Otter goes there every night and watches — on the chance, you know, just on the chance!’

They were silent for a time, both thinking of the same thing — the lonely, heart-sore animal, crouched by the ford, watching and waiting, the long night through — on the chance.

‘Well, well,’ said the Rat presently, ‘I suppose we ought to be thinking about turning in.’ But he never offered to move.

‘Rat,’ said the Mole, ‘I simply can’t go and turn in, and go to sleep, and do nothing, even though there doesn’t seem to be anything to be done. We’ll get the boat out, and paddle up stream. The moon will be up in an hour or so, and then we will search as well as we can — anyhow, it will be better than going to bed and doing nothing.’

‘Just what I was thinking myself,’ said the Rat. ‘It’s not the sort of night for bed anyhow; and daybreak is not so very far off, and then we may pick up some news of him from early risers as we go along.’

They got the boat out, and the Rat took the sculls, paddling with caution. Out in midstream, there was a clear, narrow track that faintly reflected the sky; but wherever shadows fell on the water from bank, bush, or tree, they were as solid to all appearance as the banks themselves, and the Mole had to steer with judgment accordingly. Dark and deserted as it was, the night was full of small noises, song and chatter and rustling, telling of the busy little population who were up and about, plying their trades and vocations through the night till sunshine should fall on them at last and send them off to their well-earned repose. The water’s own noises, too, were more apparent than by day, its gurglings and ‘cloops’ more unexpected and near at hand; and constantly they started at what seemed a sudden clear call from an actual articulate voice.

The line of the horizon was clear and hard against the sky, and in one particular quarter it showed black against a silvery climbing phosphorescence that grew and grew. At last, over the rim of the waiting earth the moon lifted with slow majesty till it swung clear of the horizon and rode off, free of moorings; and once more they began to see surfaces — meadows wide-spread, and quiet gardens, and the river itself from bank to bank, all softly disclosed, all washed clean of mystery and terror, all radiant again as by day, but with a difference that was tremendous. Their old haunts greeted them again in other raiment, as if they had slipped away and put on this pure new apparel and come quietly back, smiling as they shyly waited to see if they would be recognised again under it.

Fastening their boat to a willow, the friends landed in this silent, silver kingdom, and patiently explored the hedges, the hollow trees, the runnels and their little culverts, the ditches and dry water-ways. Embarking again and crossing over, they worked their way up the stream in this manner, while the moon, serene and detached in a cloudless sky, did what she could, though so far off, to help them in their quest; till her hour came and she sank earthwards reluctantly, and left them, and mystery once more held field and river.

Then a change began slowly to declare itself. The horizon became clearer, field and tree came more into sight, and somehow with a different look; the mystery began to drop away from them. A bird piped suddenly, and was still; and a light breeze sprang up and set the reeds and bulrushes rustling. Rat, who was in the stern of the boat, while Mole sculled, sat up suddenly and listened with a passionate intentness. Mole, who with gentle strokes was just keeping the boat moving while he scanned the banks with care, looked at him with curiosity.

‘It’s gone!’ sighed the Rat, sinking back in his seat again. ‘So beautiful and strange and new. Since it was to end so soon, I almost wish I had never heard it. For it has roused a longing in me that is pain, and nothing seems worth while but just to hear that sound once more and go on listening to it for ever.