DB5 Entry -- The Ipso Facto

Robert Newlon looked over his shoulder as he hurried through the gallery. Many would come after him. He must be the first there.
The wind howled through the corridor, voices echoing along it like ghostly hallow, and he clutched the letter, worrying not that the wax would stick to his doublet even though it hadn’t fully cured before he’d left his writing table.
This was his chance to right the wrong that had gone so wrong. Years of persecution all in the name of a lie. 
He’d known. And done nothing.
The guilt weighed heavy upon Robert’s conscience. Though not on his heart. Many said that Robert didn’t have a heart and he feared them to be right.
The moon shone through the rose window in the nave, her ghostly light making a mockery of the vibrant stained glass, casting the pattern to the stone floor like a specter. He passed over it, a mere shadow among the design, his feet swift and silent, for the night guard would soon be along.
The tunnel beckoned, a yawning mouth from the bowels of Hell, which was where Robert feared this night might send him if he didn’t reach the vault in time.
The moon’s small but necessary light quit as he entered the dark tunnel and Robert paused for his eyes to adjust. It was disconcerting, this sudden winking out of the light as if the world ceased to exist. 
For Robert, it might very well do so.
He shuddered. He couldn’t think like that. He must see to his mission and reach the sanctuary so this travesty would not continue.
He drifted his fingertips along the wall, feeling his way to the turn.
Cold, unrefined stone met his touch. This part of the church hadn’t been part of the original. Few knew of its existence. 
His family knew and that was all that mattered.
The clock struck the hour in the square, its chime echoing along the walls so that Robert felt it in his very bones. He picked up his pace. Time waited for no man.
The first turn came upon him and Robert counted the three steps he needed to cross its width. His fingers encountered the wall on the other side and he breathed a sigh of relief. The next would take him to his destination.
Thirteen more steps—Robert crossed himself—and he’d be there.
Twelve. Eleven. Ten—
“Good morn to you, Sir Robert.”
Arms grabbed him and someone struck flint, the spark turning to fire atop a torch.
The lords. They were already here.
And Robert was sunk.
“ ’Tis time for you to cease,” said Lord Teabing, shaking his head as if Robert were a child. Pompous bastard.
“ ’Twill not change anything,” said Sir Hugh. Sir Hugh. ’Twas what he liked to be called in those special private moments Robert had heard of. Robert shook his head.Sir Hugh liked to play the woman in those private moments.
“I suppose you must do as you will,” said Lord Dunley. Robert never understood how Dunley, always a practical man, called these men friends.
But it was no matter. The chamber he sought was just beyond. All he needed was reach to it and all would be well.
“Come, let us see what you carry.” Teabing brandished the torch as if he meant to use it upon Robert’s person.
But he would not. At least, not until he found what he sought.
Robert shoved the document beneath his cloak. “’Tis not for your eyes.”
Teabing held out his hand.
Robert spat upon it.
“You silly man.” Teabing was one to talk. He had taken to wearing maquillage like a French whore to cover the pox marks that whore had given him.
“Robert, you have no recourse. Hand it over.” Dunley bothered to smile.
The charm that worked on the ladies at court had no effect on Robert.
“The Tower hasn’t had a guest in years, Newlon. I doubt you wish to be the first, for the guards have been honing their skills.”
Robert swallowed. The threat was real. Robert had been a so-called guest in the Tower years ago. ’Twas why he must stop the lies. Far too many had paid the ultimate price for the Pope’s power.
He stepped back.
“Come, Robert. ’Tis over.” Lord Dunley took another forward. They were driving him from his destination, clever bastards.
No. He would not fail.
He scrambled from their hold, his cloak hampering their clutches, and Robert broke the chain keeping it around his shoulders.
He lunged into the room, the moon’s angle almost beyond the mark upon the wall, and clawed at the left corner. There, the smallest indent. A latch inside that, when pressed, would open.
It did.
Robert shoved the letter inside, wishing he had the time to place it properly, but ’twas more important that it be survive intact than unwrinkled.
“Give us that!” 
The lords flew into the chamber on their rage, but ’twas too late, for, with the smallest of movements, Robert sealed the compartment. Without the knowledge to open it, nor the moon to show them, they’d never find the lock.
Teabing’s sword pierced his gut just as the moon disappeared behind the merlon. Robert looked down, time now allowing him to see each moment stretched out before him as if it took an hour. 
But it was not an hour. And it would not take him one to die.
Robert closed his eyes, refusing to answer their questions. So many questions. What had he done with the letter? Who was it addressed to? What had it said?
Ah, if only time would give them longer they might learn what he knew, but he’d take it to the grave with him. For, someday, his descendant would learn its secrets. Someday, when the world was more prepared.
***
Blythe Newlon stood in front of her family vault and handed the letter to her husband, Daniel. 
The answer is Sophie.