[he was still half-expecting a silly answer, but Kuroba's reply just sealed his suspicions. For lack of a direction, he's following after him to the door, hands in pockets as he stands over him to watch]

I take it that this 'doctor' is an alien, yet has somehow contrived to look exactly like me?

That's somewhat farfetched for a double.

[In fact, almost too great. The differences between 'alien' and 'human' are very wide]