Conan had promised to listen, and so he does. All through the entire explanation, no matter how shocking it became.

He had toyed with the idea of theorizing about other realities. Between the the current situation and hearing of the odd similarities between Sherlock;s world and the fictional world created by Doyle.... It seemed possible. Even likely. Even if there was no way to prove the theory.

But this... this was something else altogether. Yet how else could John know? John Watson was not a real person in Conan's world. And he knew very well that there was no one here who knew the secret.

And even more so, how else could he know of Hattori and Hakuba. Conan had never mentioned their names in Tushanshu.

Conan frowns deeply as he considers everything.

"When you have eliminated the impossible, whatever remains, however improbable, must be the truth. That is the thing to say at a moment like this, isn't it? But even so, this is very improbable."

He tips his head back against the couch and stares at the ceiling.

"Is there anything you have that could serve as proof?"