Edward began to be afraid of having pushed too far forward, and of finding himself endangered in the heart of France, confronted by an army which would soon be stronger than his own.  Some chronicles say that Philip, in his turn, sent a challenge either for single combat or for a battle on a fixed day, in a place assigned, and that Edward, in his turn also, declined the proposition he had but lately made to his rival.  It appears, further, that at the moment of commencing his retreat away from Paris, he tried ringing the changes on Philip with respect to the line he intended to take, and that Philip was led to believe that the English army would fall back in a westerly direction, by Orleans and Tours, whereas it marched northward, where Edward flattered himself he would find partisans, counting especially on the help of the Flemings, who, in fulfilment of their promise, had already advanced as far as Bethune to support him.  Philip was soon better informed, and moved with all his army into Picardy in pursuit of the English army, which was in a hurry to reach and cross the Somme, and so continue its march northward.  It was more than once forced to fight on its march with the people of the towns and country through which it was passing; provisions were beginning to fall short; and Edward sent his two marshals, the Earl of Warwick and Godfrey d’Harcourt, to discover where it was practicable to cross the river, which, at this season of the year and so near its mouth, was both broad and deep.  They returned without having any satisfactory information to report; “whereupon,” says Froissart, “the king was not more joyous or less pensive, and began to fall into a great melancholy.”  He had halted three or four days at Airaines, some few leagues from Amiens, whither the King of France had arrived in pursuit with an army, it is said, more than a hundred thousand strong.  Philip learned through his scouts that the King of England would evacuate Airaines the next morning, and ride to Abbeville in hopes of finding some means of getting over the Somme.  Philip immediately ordered a Norman baron, Godemar du Fay, to go with a body of troops and guard the ford of Blanche-Tache, below Abbeville, the only point at which, it was said, the English could cross the river; and on the same day he himself moved with the bulk of his army from Amiens on Airaines.  There he arrived about midday, some few hours after that the King of England had departed with such precipitation that the French found in it “great store of provisions, meat ready spitted, bread and pastry in the oven, wines in barrel, and many tables which the English had left ready set and laid out.”  “Sir,” said Philip’s officers to him, as soon as he was at Airaines, “rest you here and wait for your barons and their folk, for the English cannot escape you.”  It was concluded, in point of fact, that Edward and his troops, not being able to cross the Somme, would find themselves hemmed in between the French army and the strong places of Abbeville,