The main and decisive blow was of course to be delivered by Harispe, Musnier, and Reille, who were to cross the river at a point where the Spaniards were unlikely to make any serious opposition, since it was outside their chosen ground of defence, and was clearly watched rather than held. If 20,000 men crossed here, and succeeded in establishing themselves south of Valencia by a rapid march, Blake would find his lines useless, and would be forced to fight in the open, in order to secure a retreat southward, or else to shut himself and his whole force up in the entrenched camp around the city. Suchet could accept either alternative with equanimity: a battle, as he judged, meant a victory, the breaking up of the Spanish army and the capture of Valencia. If, on the other hand, Blake refused to fight a general engagement, and retired within his camp, it would lead to his being surrounded, and the desired end would only be deferred for a few days. There were only two dangers--one was that the Spanish general might abscond southward with the bulk of his army, without fighting, the moment that he heard that his enemy was across the Guadalaviar. The second was that, waiting till the French main body was committed to its flank march, he might break out northward by the three bridges in his hands, overwhelm the Neapolitans, and escape towards Liria and Segorbe into the mountains. Suchet judged that his enemy would try neither of these courses; he would not be timid enough to retreat on the instant that he learnt that his left wing was beginning to be turned; nor would he be resourceful enough to strike away northward, as soon as he saw that the turning movement was formidable and certain of success. Herein Suchet judged aright. At nightfall on the 25th-26th of December two hundred hussars, each carrying a voltigeur behind him, forded the Guadalaviar at Ribaroja, and threw out a chain of posts which brushed off a few Spanish cavalry vedettes. The moment that the farther bank was clear, the whole force of Suchet’s engineers set to work to build two trestle-bridges for infantry, and to lay a solid pontoon bridge higher up for guns and cavalry. A few hours later Harispe’s division began to pass--then Musnier’s, lastly Boussard’s cavalry. The defile took a long time, and even by dawn Reille’s three brigades had not arrived or begun to pass. But by that time ten thousand French were over the river. The Spanish vedettes had reported, both to their cavalry generals at Aldaya and to Blake at Valencia, that the enemy was busy at Ribaroja, but had not been able to judge of his force, or to make out that he was constructing bridges. Their commanders resolved that nothing could be done in the dark, and that the morning light would determine the character of the movement[54]. [54] So Suchet’s narrative (_Mémoires_, ii. pp. 214-15). Belmas says that only one bridge was finished when Harispe and Musnier passed--the others after dawn only.