Lad and the Devil agree to build a bridge together. The bridge will link the east bank of the Kentish Stour and the western bank of the Welsh Wye; and Lad needs it to visit his wife, who otherwise would be weeks' of walking away. Now, the bridge must be built all in one night, for if it is unfinished in daylight it falls into the rivers as a heap of stones. 'I'll help you, Lad, and we'll agree to labour together at the task,' says the Devil; 'but the first soul to cross it shall be mine; such is my bargain.' 'Very well,' says Lad; and Lad knows that the Devil believes the first soul across will be Lad's wife--or Lad himself. So they two come at sunset, and the Devil carries a great brass hammer, and Lad carries only an old bone. 'You'll neither drives piles nor split rock with that,' said the Devil. And Lad replied: 'but I shall try, and it was my labour, not my success, you bargained for.' So the Devil had no choice but the do all the hard work himself, setting the piles and laying the heavy stones; whilst all Lad had to do was to set the slate to cope the parapet, and he did so by thwacking it into place with his bone. And before the dawn the bridge was finished, and the sky began to blush. And the Devil put out from his throat Lad's own voice, as the Devil can do, and called Lad's wife to come try the new bridge and visit her husband. But Lad was quicker, and with all his strength he hurled his bone over the bridge. His dog, Siôn Cent, ran after the bone and over the bridge, and laughingly Lad said: 'our deal is done, for there's your soul.' But the Devil shook his head, and said 'there's no soul in a dog, my Lad. The bargain is unfulfilled.' And Lad began to tremble with fear.
Just then, as the dawn swelled over the horizon, Lad saw his wife start on the Wye-side of the bridge and come towards him. All his lightness of spirit left him then, and he felt a terror and dread; for he loved his wife and could not abide the thought that she would become the Devil's. So he ran himself onto the bridge, and met his wife halfway. 'If you cross the Devil will take you,' he said. 'And if I cross, the Devil will take me!' 'What then?' replied his wife, 'must we abide on the middle of this bridge forever?' 'Return you to the far side, and I shall take myself back to the near, and though we never see each other again we shall at least escape the devil's clutches.' 'No!' cried his wife, 'I would rather die than face such a fate!' 'Then we must stay here,' said Lad, embracing his wife in the midst of the bridge, 'until we perish of old age! For we cannot go on.' But the sun was up now, and a piece of slate that Lad had laid carelessly fell away as the couple leant against it, and fell into the river: for an old bone does not settle a coping slate as well as a coping hammer. So the bridge was incomplete by daybreak, and all tumbled to loose blocks in the daylight. But Lad and his wife, clasping close together, fell into the river--whether the Wye or the Stour it is not possible to say, for they stood exactly in the midst of both yet wholly in the realm of neither. Certainly they were not seen again, and some said they fell into the waters and were drowned and so went to hell, and other said they dropped into some new land and began a new life, and the Devil was thwarted.