On Saturday mornings when the peaks and trenches of London's skyline emerged from the fog and filled the ground from here to the horizon with reflected sunlight and chimney smoke, Remus would answer mail on the couch near the window. Letters would come in from all over the world; good news and bad news, thrilling surprises or the latest heartbreak, all contained in their own white roll of paper, would be stacked on the coffee table, sorted, and replied to.

Peter would owl from Portugal to report on the latest rumblings of dark wizardry there. Sometimes, James would write to invite Sirius and Remus out for a drink at the local pub or to Germany to scare up a Death-eater or two, and Lily would write almost immediately after to warn them not to listen to a word James Potter says.

On these mornings when Remus couldn't pretend that a life could be contained in four walls, Sirius would spread himself along the fire escape like surf across sand, and Remus would soon abandon his dutiful responses – thank you for your letter, it's always good to hear from you – and fold into an open window with a book pressed against his knees.

"What would you do if I were gone?" Sirius would ask, staring out at waking London around and below, fingers curling just above his stomach.

"Thank Merlin for the peace and quiet, probably," Remus would respond, and Sirius would shake his head, eyes restless, hair tumbling across his face.

"I mean it. What would you do if you wake up some morning, and I'd been killed on whatever crazy kamikaze run Moody sets us next?"

And Remus would pause with his thumb covering the page number and listen to car horns echoing from the M40 before replying, "I don't know."

And no matter how many time Sirius asked, the answer remained the same. It was the question that began to change, becoming "Do you think we'll make it out of this?" and then "What the hell are you playing at, Moony?" and finally "Are you on my side or not?"

And even as life started crumbling and the letters stopped coming, first Lily and James's and then Peter's, Remus could find no other answer than "I don't know," "I don't know," "I don't know."