"It's for when you fuck up and need a place to hide," he replied shortly, a scowl on his face. Not that that would surprise the other man. Rook scowled at him a lot. It was probably safe to say that if Rook was ever looking at Dax, he was doing so with some sort of sour expression on his face. Dax just seemed to inspire that kind of look.
"The house is under the Fidelius Charm, so don't ever show that to anyone, no matter how much you think you trust them, either keep it safe or remember it and burn it." He didn't think he had to tell Dax that his and his father's lives might literally depend on Dax never showing the paper to anyone, but he would if it appeared the other man wasn't taking it seriously enough--or if it seemed like Dax thought there might be exceptions to the rule. As far as Rook was concerned, there weren't any. This was one thing he and Edgar disagreed on, but if the elder Bones wanted Dax to be able to send people there in an emergency, he'd have to tell him himself; Rook wasn't going to do that and put them all in danger like that.