If it were Zagreus, he might actually have recognized him more quickly. That sort of insanity gives off a very distinct aura. Or, you know, if he were awake and his brain properly focused.

"You," he repeats with a sigh. "I was looking for the TARDIS," he explains without explaining. "But you'll probably have to do -- I'm you, from the future. Ish. I'll explain later, but I need a telepath right now."