A mounted officer brought similar orders to Terence. Half an hour after receiving them the corps was on the march. The instructions were brief and simple:

_"You will endeavour to harass Soult as he retreats across the Tras-os-Montes, and try to head him off to the north. Act as circumstances may dictate."__

The service was a dangerous one, and Terence felt that it was a high honour that the general should have appointed him to undertake it, for he assuredly would not have sent the corps on such a mission had he not considered that they could be relied upon to take care of themselves. They would be wholly unsupported save by parties of peasants and ordenanças; they would have to operate against an army broken, doubtless, by defeat, but all the more determined to push on, as delay might mean total loss.

He followed the line of the Vouga to the point where it emerged from the hills, crossed these, and came down upon the Douro some ten miles above San Joao, at nearly the same spot where he had before made the passage when on his way to join Romana.