Above him blazed the Egyptian noon.  How long he had lain there, he didn’t know; but the infidels had attacked at night.  There had been no way to advance and no retreat:  they had fought where they stood, and fallen where they fought.  His brave Bayard had reared to trample the enemy; he himself had leant from the saddle to swing at a man on his off-side.  Neither had noticed the treacherous cur who slunk in to stick the stallion in the gut.
Yet, even with a mortal wound, the war horse still had killed his man—killed him screaming under his hooves—and then staggered.
How many Nicolas himself had slain he was not sure:  dozens, likely.  He had thought the battle still hung in the balance.  Certainly, even surprised in the dark, they had given good account of themselves.  The Moors had not overcome them easily:  not the Crusaders who had taken Damietta!  Their right was conquest:  to take the lands of the east from the Moors, free the Holy Land, and bring it back to Christ.
It was pure ill chance that, even as Nicolas realized his horse was going down and swung his leg over to drop free, his boot had caught in the near stirrup.  Still, he could have wrenched it loose … had Bayard stayed a little longer on his feet or fallen to the other side.
The weight of the horse crushed him.  As his head struck the ground, his ears rang in his helmet.  He did not recover from the swound until the press of battle had broken.  Bayard’s blood oozed through his mail:  it was not until later that he realized it mingled with his own.  The full weight of the horse pinned him up to the waist; and he could not get purchase to drag himself free.
Eventually, the agony resolved itself:  there was a dark, leaden ache from the dunt on his crown; the broad crush under Bayard; the shrill stab in his shoulder when he tried to lift himself.  It was a while before he realized that an arrow also stuck from his arm, just above the elbow.  He had not even felt it hit.

As the sky brightened, the sounds of battle dimmed.  Soon, the scavengers would come:  the vultures that circled, the dogs from the midden, the jackal women who followed every army.  They would come to pick the dead.
He could not reach his dagger, the cross of last resort; but he held it in his mind and prayed to the Lord above that he would take him before the thieves searched the field.  To die of wounds was a rightful end for a knight.  Please God it need not be his fate to die of a slit throat.
“Let me die like a trueborn knight,” he prayed.  “Let word go back to my family so my father may know that Nicolas, second son, died honourably to the credit of his house.”
He thought of the last time he’d seen his home, after he had taken the cross and made his vows to the Bishop in Chester, and ridden home to Brabant on that long journey to Jerusalem.  His mother had hidden her fears beneath her pride; but his father had berated him for throwing away the good position he had bought him.  He had confessed the events in Wales:  Gwyneth’s death, the accusation, and Lord De La Barre’s suggestion that he take the cross.  He could not be sure of his father’s response.  True, he had not sullied the family name by a trial; but he did not know if he would be castigated for failing in courage to demand wager of battle and the justice of God.  He did not expect to be cursed for a fool.  In simple words for the simple-minded, his father explained how his dalliance betrayed his lealty.  “It was De La Barre who killed the wench,” he thundered.  The treachery was too immense to grasp.  Nicolas caught only at “wench”, defended his lady, and earned a clout on the ear from his outraged sire.
He had left the next day, and been glad to depart.  Still, on the long journey south, the truth of his father’s words sank deep.  He had sworn tricked oath to shield a killer.  It shadowed the pure purpose of crusade.  (Not that all was pure in the Holy Land.  Men were men, even when they followed the paths of Heaven.)
Perhaps their sins had caught them, Nicolas thought.  Perhaps pure purpose had become too gravely alloyed with the passion for power and the greed for gold.  He thought of the dissension among the great lords after the capture of Damietta—and his own part in its sack.  There had to be a reason the Lord had left their side:  had he still been with them, their cause must have triumphed.  Their loss was the Lord’s will.  (And it would be the Lord’s will if his throat be slit and a lowborn thief strip his corpse.)

Steps.
Behind him.
Too close, and coming closer.
Nicolas fumbled again, through the pain in his arm, at least to reach some one of his weapons to defend himself.  His doom might be upon him; but he might yet die fighting.
A dark shape.
He could not reach.  With a gasp, he sank back—and then twisted round, striving to see.  Face to face.  Face to face.  Not a blow from behind, please God.  Let him face his fate.
The robed figure passed before the sun, and knelt.
“Effendi, for you the war is over.  You are a prisoner of my lord, Sultan Al-Kamil.”
It was Frankish.  Heavily accented, but understandable.  Nicolas blinked, trying to see clearly, though the sun behind the man darkened his features as it haloed his head.
“I bring men to carry you to Cairo.”
What was this?  Other shadows dallied with the sun.
“It is hot, and you are injured.  We will bind your wounds.  But first….”  The figure knelt closer.
“Drink, effendi.”  It offered a waterskin.
There can be no keener torture for Christian knight than succor from the paynim.

NOTES

This story was originally written for the Dead Dog Party after FK Fic Fest 2011 to gnosticdiva’s prompt, “Nick’s backstory (according to Word of God a.k.a. JP) is that he was imprisoned and tortured by Muslims, setting the stage for his disillusionment with the Catholic faith and Janette seducing him into the realm of the undead.  At (possibly) another point, Nick was severely injured in battle to the point of death.  Write something that references, incorporates or otherwise makes sense of these two ideas.”.  “The Sun of Cairo” was posted to FK Comment Fic on 16 September 2011.  The version here has been somewhat revised.  It has also been posted to AO3.

The flashback to the episode “Queen of Harps” describes how Nicolas de Brabant—a young knight serving as aide to Sir Raymond DeLabarre in Wales—was framed for the murder of Lady Gwyneth, with whom he had fallen in love.  The actual killer had been DeLaBarre, who had seen her as a focus for local rebellion.  He then instructed his aide to take the cross as an alternative to trial.

The term ‘wager of battle’ was used in England to refer to trial by combat.

Much effort has been made by fans to correlate the events of Nicolas de Brabant’s fictional life with actual historical events.  It seems likeliest that he took part in the Fifth Crusade (1217–1221).  This was an attempt to take back Jerusalem and the rest of the Holy Land by first conquering Egypt.  After more than a year of siege, the crusaders did succeed in taking the city of Damietta; but in July 1221 they were de­feat­ed when they tried to capture Cairo.  Their march was halted when the Nile flooded; and Sultan Al-Kamil ordered dykes opened to fill a dry canal behind them, trapping them in between, at which point his forces made a successful night assault.  (You can find more information in the Wikipedia article on the Fifth Crusade.)