Andrew draws in a sharp breath to tell him that he was on his way to the TARDIS, thank you, and would have been there already and merged with his other selves if the Master hadn't picked him up. It does occur to him, though, that it might be best not to share the information that she's nearby...or that there are probably more of him scurrying about, lest the Master decides he's gotta catch 'em all.

"Why would I want to try?" he grouses. "And sorry if I don't believe in your altruism."