Rose shoves the screwdriver into the console; outside, the Doctor presses his device into one of the cones. Like a well-oiled machine, these two. He runs around to the other two cones, shouting in to Rose: "What's the line doing?" Holding. The line is holding. Jackie stands inside, watching over Rose's shoulder, wondering at their work: "You even look like him?" Rose thinks, and smiles. She supposes that she does. "You've changed so much," says Jackie, forgetting about the ghosts of the shift and remembering the ones she used to talk to. Rose shrugs; for the better, she's changed. Jackie shrugs, whispering: "I suppose." Rose turns to her mother, ready to begin this fight once more: "Mum, I used to work in a shop!" Jackie gets defensive: "I've worked in shops. What's wrong with that?" Rose declines to draw the diagrams of saints: "No, I didn't mean that." Jackie knows full well what she meant: "What happens when I'm gone?" Rose is shocked, and tells her not to talk like that. "No, but really. When I'm dead and buried, you won't have any reason to come back home. What happens then?" Rose doesn't know. "Do you think you'll ever settle down?" Rose doesn't know: "The Doctor never will, so I can't. I'll just keep on traveling." And keep on changing. We get hard. "And in forty years' time, fifty, there'll be this woman, this strange woman, walking through the marketplace on some planet a billion miles from Earth. She's not Rose Tyler. Not anymore. She's not even human..." And before the Doctor interrupts, let's take a second to...nope, Jackie's got it covered. She's right, Rose is wrong. The Doctor interrupts, and Rose shouts back out to him: "The scanner's working, it says Delta One Six." He stands shouting at his triangle of cones, 3/5 of a pentagram, crackling with excitement. "Come on, you beauty!"
Yvonne puts on her shades: "And...we're into ghost shift." The computer is online; the veil is lifted. The ghosts descend. History makes a visit.
The Doctor's triangle manifests a ghost, right in the center. The points of the triangle connect, forming a pyramid of electric blue science over the ghost. You don't have to reduce it to science: that's all magic is, science we don't know. Every week a séance, every week an exorcism. As far as you can take it. And every week somebody goes home, or into death.