Doctor: Christopher Eccleston (Ninth Doctor)
Companions: Billie Piper (Rose Tyler)
John Barrowman (Jack Harkness)
Kate Harvey – Nightclub Singer
Albert Valentine – The Child Jamie
Florence Hoath – Nancy
Cheryl Fergison – Mrs Lloyd
Damian Samuels – Mr Lloyd
Robert Hands – Algy
Joseph Tremain – Jim
Jordan Murphy – Ernie
Brandon Miller – Alf
Richard Wilson – Dr Constantine
Noah Johnson – Voice of the Empty Child
Dian Perry – Computer Voice
Directed by James Hawes
Written by Steven Moffat
Script editor Elwen Rowlands
Produced by Phil Collinson
Executive producer(s) Russell T Davies
Incidental music composer Murray Gold
Production code 1.9
Series Series 1
Length 1st of 2-part story, 45 minutes
Originally broadcast 21 May 2005
The episode opens with the Doctor and Rose in the TARDIS chasing a mysterious metal cylinder through time and space. The cylinder, marked as dangerous, skips in and out of the time vortex before landing somewhere on Earth. The Doctor lands the TARDIS in London, and he and Rose walk over to a nearby restaurant to ask about the cylinder. The Doctor uses a microphone to ask if anything has fallen from the sky recently, only to hear an air raid siren and realise that they are in London during The Blitz of World War II. Meanwhile, Rose spots a young boy asking for his mummy and follows him to a rooftop, where she tries to use the ropes of a barrage balloon to climb to the child, and is carried away. The Doctor heads back to the TARDIS looking for Rose but instead is shocked to hear the TARDIS phone on the outside of the box is ringing. As he is about to answer, a young woman named Nancy appears and warns him not to. Answering the phone anyway, the Doctor hears a young boy on the line, asking "Are you my mummy?" before the call ends. Confused, the Doctor follows Nancy down the street.
Meanwhile, Rose is trapped on the balloon as the air raid happens and is spotted by Captain Jack Harkness, who is posing as an RAF officer. Harkness slips out and rescues Rose using the tractor beam from a Chula warship that he is piloting. At the same time, the Doctor catches up to Nancy and a group of children who have broken into a house to eat a dinner that's been left out by the owners who are taking shelter from the air raid. The Doctor sits down to eat with them and asks if they've seen Rose before asking Nancy about the phone. Nancy asks the Doctor to leave, but before he can the child in the gas mask knocks at the door asking for his mummy. Nancy panics and orders everyone to leave out a separate entrance. She bolts the front door and refuses to let the child in. When the Doctor asks why, she tells him that it's not a real boy, and if he touches it, he will become "empty" like it is. The phone rings in the hall and the boy continues knocking, but disappears as the Doctor opens the door.
On the Chula ship, Captain Jack introduces himself to Rose and flirts openly with her on top of his ship, which is camouflaged, and tethered to Big Ben. They stand on top of the ship and open a bottle of champagne. On the streets, the Doctor catches up to Nancy and questions her again about the boy. She tells him that the item that fell from the sky is related to the boy, and that it's under heavy guard nearby. She also admits that she is caring for the other children because she lost her brother to a recent air raid. The Doctor gives her some encouraging words about the future and they set off together for a nearby hospital. Back at Big Ben, Captain Jack plays music and dances with Rose before admitting that he's a former time agent and that he has an item for sale. Rose bluffs him, telling him that he needs to take her to her partner before she can buy it.
At the hospital near where the cylinder crashed, the Doctor encounters Doctor Constantine caring for a room full of patients that all have the same symptoms. Doctor Constantine demonstrates that they are not deceased due to their injuries. He starts to explain that the first patient with these symptoms was Nancy's brother Jamie, but before he can finish he transforms into another gas mask-clad victim. Rose and Jack arrive at the hospital in time to save the Doctor from the transformed Constantine and patients. Escaping deeper into the building, Jack again attempts to sell the warship to the Doctor who gets Jack to admit that it is only a Chula medical ship. Jack denies that it has anything to do with the current outbreak.
The episode ends as the three are trapped in a room while the transformed patients converge upon them, all asking for their "mummies". Nancy, having returned to the house for more food, is similarly cornered by Jamie.