They may either have lost their way in the darkness, or fallen into the hands of the enemy.

However, I shall not give them up for another half hour." The firing was now abating, and presently died away completely; except for a few scattered shots, showing that the allies had been halted where they stood, and were no longer pressing forward.
Another hour passed, and Desmond's comrades were still absent.
In the meantime, the general had called together the colonels of the several regiments, had explained the situation to them, and repeated Vendome's orders.

The news came like a thunderbolt upon them, for the din of firing round the village had completely deadened all distant sound, and they were wholly unaware of what was passing in other parts of the field.
"I must leave the matter to your individual discretion," the general said.

"Those of you who think your men can be relied on, can try to escape and join the marshal in a body.

Those who have not that confidence in their regiments--and indeed some of these have been almost annihilated--had best tell them to scatter.