The Doctor and Companions meet K-9 in the hall, and the Doctor calls him a "good boy," and the four set off together.
While they're doing that, Mickey busts into a computer class and addresses the unhearing children: "Listen, everyone, we've gotta get out of here." Nothing. The children are all plugged in. He waves a hand before a child's face: nothing. They're caught between waking and sleep, plugged into the mind of God but insensate. In a half-way state. You could spend your life that way, and wake up thirty years later, childless, wondering where Peter Pan went after all.
The Doctor, Companions, and Kenny reach the kitchens; the Doctor takes his screwdriver to one of the barrels, but once again can't get in. "Finch must've done that -- I can't open them." K-9 -- this tin dog, this meek metal soul between them all -- speaks up: "The vats would not withstand a direct hit from my laser. But my batteries are failing." Right. The Doctor: "Everyone out the back door. K-9, stay with me." Sarah Jane, Rose, and Kenny run to the back door, leaving the Doctor crouching with K-9.
Mickey can't seem to get the head computer to stop transmitting -- until he notices the plastic covering the wires, and follows the bundle casing around the wall, finally reaching a single plug. Cute. He unplugs it, and all the computers go dead; the socket explodes with sparks. (It does not, however, turn into David Tennant.) "Everyone get out, now!" The children obediently head for the door.
The Krillitanes bound down the stairs and turn back into humans, heading down the hall.
The Doctor arranges the oil vats around K-9. "Capacity for only one shot, Master. For maximum impact, I must be placed directly beside the vat." The Doctor protests: "But you'll be trapped inside!" K-9 confirms this. "I can't let you do that," says the Doctor. "No alternative possible, Master." The Doctor hears the screeching coming closer, and his face goes hard and sad. "Goodbye, old friend." "Goodbye, Master." Brief, this round. "You good dog," says the Doctor sweetly, and K-9 wags his tail: "Affirmative." He pets the dog and dashes away; K-9 trundles up to the barrel.
The Doctor comes running out and slams the door behind him, locking it. "Where's K-9?" asks Sarah Jane. Of course. "We need to run," he says, sidestepping the issue. Of course. She doesn't move. "Where is he? What've you done?" The Doctor pulls her bodily away.
Finch and his brothers enter the kitchen: "When you find him...eat him if you must, but bring me his brain." Interesting that it wasn't a bluff: Finch really does want the Doctor's wisdom running the show. That's very cool; it lends the whole thing some respectability. Unless it's a related brain thing of Finch's, like eating the brains, which I don't like as much. I expect more from Finch.