It was already very ancient; its foundation had been laid by Roman soldiery; in the lapse of ages much of it had sunk, and every here and there, for a few hundred yards, it lay submerged below the stagnant waters of the fen.
About a mile from Kettley, Dick came to one such break in the plain line of causeway, where the reeds and willows grew dispersedly like little islands and confused the eye.

The gap, besides, was more than usually long; it was a place where any stranger might come readily to mischief; and Dick bethought him, with something like a pang, of the lad whom he had so imperfectly directed.

As for himself, one look backward to where the windmill sails were turning black against the blue of heaven--one look forward to the high ground of Tunstall Forest, and he was sufficiently directed and held straight on, the water washing to his horse's knees, as safe as on a highway.
Half-way across, and when he had already sighted the path rising high and dry upon the farther side, he was aware of a great splashing on his right, and saw a grey horse, sunk to its belly in the mud, and still spasmodically struggling.

Instantly, as though it had divined the neighbourhood of help, the poor beast began to neigh most piercingly.

It rolled, meanwhile, a blood-shot eye, insane with terror; and as it sprawled wallowing in the quag, clouds of stinging insects rose and buzzed about it in the air.
"Alack!" thought Dick, "can the poor lad have perished?
There is his horse, for certain--a brave grey! Nay, comrade, if thou criest to me so piteously, I will do all man can to help thee.