The accident had been caused by a strange and savage dog suddenly springing at the horses' heads as the carriage was nearing the outer gate.  The night was very dark, and the horses, which were young and full of spirit, being startled by the unexpected attack of the dog, which belonged to some passing traveller, sprang violently out of the road, and, easily crashing through the wooden fence, which happened to be unusually weak just at that part, carried the carriage along with them to the very edge of the chalk-pit, spite of all the efforts of the coachman to hold them in; so that when the people of the Manor-house came to the rescue, they found the carriage and its occupants in a most critical position.