Because this two-parter takes place in the present day, we begin at the end of "Rose," that slow-mo run, as we enter the story proper. The TARDIS fades in at the crook of the street where Rose's mum lives, in the Crap Estates. We'll see them here a lot, because that's the set they have. The piano is worried, but Rose and the Doctor are giddy as they hop out of the big blue box. The Doctor leans back against her doors and folds his arms, as Rose fairly hops about asking for clarification on just how long she's been gone, subjective to the folks she left behind. ("Excellent question, Rose.") He confirms that it's only been twelve hours, and they giggle at each other, and she sets off to see Jackie. He asks what she plans to say, and she nearly makes him snort trying to choose between "the year five billion" and "sleepover at Shareen's." She turns and says once, "Don't you disappear!" He smiles at her and wiggles his eyebrows, because the idea is so unspeakably weird, and she takes off for the flat. He settles back against the TARDIS to wait. We cut back and forth between Rose taking the (many, many) stairs up to the flat, and the Doctor loitering around in the courtyard. The music goes nuts, downshifting like in the original When A Stranger Calls or the scary THX sound from the movie theater, as the Doctor spots a poster on a lamppost opposite. Coming closer, we see a picture of Rose, with the caption, "Can You Help?"
Upstairs, the Tylers' apartment is not looking so very livable. Rose comes in yelling and -- I guess not for the first time -- blaming Shareen's emotional issues. Jackie Tyler walks in with a cup of tea, and is shocked to find Rose grinning at her: "So, what's been going on? How've you been?" Rose sequential-processes that her mum's freaking out, and jokes that it's "not the first time" she's been out all night, and Jackie drops her teacup, shattering it. The Doctor, downstairs, looks like he's been punched in the box, and he takes off towards Rose's flat. Jackie starts freaking out and getting snot all over Rose, who's confused by all the drama and sobbing until she spots, over her mother's shaking shoulder, a bunch of piles of different versions of the poster the Doctor found downstairs. The Doctor comes running in trying to explain that it's been twelve months, not hours, and Rose takes her time understanding this concept before the Doctor laughs nervously: "You've been gone a whole year. ...Sorry?" Jackie looks back to her daughter and strokes her hair, as Rose looks down, concerned and sad.