Regulus too fixated on that explanation; it was far better than the alternative as far as he was concerned. "Yes... Yes, perhaps that is what happened," he said, releasing a slow breath. "I certainly hope so, at least."
Anything else he might have said was interrupted by a tapping on the window; he moved swiftly to open it, letting in a strange owl he didn't recognize. It delivered its message and departed without waiting for a treat in payment.
Frowning, he opened the letter - and grew pale anew, gripped by icy fear at the blatant threat. He held it out for Sirius and Harry to see.