[Blimey, that's abrupt. Sam juggles his tea and almost drops it in his haste to turn and waylay the Doctor. He curses as some of it slops out onto his hand and vest, staining the fabric.]

Oi! Er, Doctor, wait. I- I can come with you, if you like. To look for the TARDIS. If you want to run tests or something... If that could help me get home-

[And that's definitely part of it, but another distinct part is getting to go inside the TARDIS!]