Rose looks round as the Doctor speaks, taking it all in -- the big thing that looks like lava and--

--there's Mickey, and he's alive, he's okay. For a given value of 'okay'. And when it turns out that was always a possibility, she almost wants to strangle the Doctor for letting her think he was dead.

But this isn't the time to be worrying about that, not with the -- what, Nestene consciousness? -- there. She reassures Mickey again and follows the Doctor as he descends closer, glancing back at her boyfriend keeping close.