The stumble saved him; the bolt would have struck his head or chest had not the horse gone nearly on his knee.
The robber had so planned his ambush that his prey should be well seen, distinct in the moonlight, so that his aim might be sure.

Recovering himself, the horse, without needing the spur, as if he recognised the danger to his rider, started forward at full speed, and raced, regardless of ruts, along the track.

Felix, who had hardly got into his seat again, could for awhile but barely restrain it, so wildly he fled.
He must have been carried within a few yards of the bandit, but saw nothing, neither did a second bolt follow him; the crossbow takes time to bend, and if the robber had companions they were differently armed.
He was a furlong or more from the spot before he quite realized the danger he had escaped.

His bow was unstrung in his hand, his arrows were all in the quiver; thus, had the bolt struck him, even if the wound had not been mortal (as it most likely would have been) he could have made no resistance.

How foolish to disregard the warnings of the grooms at the castle! It was now too late; all he could do was to ride.