This episode focuses on the impact the Doctor can have on the lives of others, and is viewed from the perspective of one such man, Elton Pope.
The episode starts with Elton explaining a pivotal meeting with the Doctor. He sees the TARDIS in Shoreditch, and hears voices from a warehouse. He goes to investigate, and is met by an alien. The Doctor then appears tempting it with a pork chop. Then Rose appears and throws a bucket of liquid over it - but the wrong bucket. The creature is angered and chases the Doctor and Rose. Elton watches the chase, and then runs when the Doctor asks if he has met Elton before.
Elton explains that events started much earlier. Whilst looking on the Internet he finds an obscure blog that mentions the Doctor, and he meets the author, Ursula, who believes his story of meeting the Doctor when he was young. They get on well together, and romance starts to blossom.
Ursula tells Elton of others who want to meet the Doctor. There is a group that Elton names Linda (London Investigations 'n' Detective Agency) that meets to discuss the Doctor. Overtime things change, and the group loses its focus - until the arrival of Victor Kennedy, who wants Linda to help him find the Doctor.
Elton is given the task of trying to meet the Doctor via Jackie. He meets Jackie in a laundrette. Although he has the task of finding a way of starting a conversation and ingratiating himself, it is Jackie that starts the conversation, and asks him round to do work that usually Mickey would have done. It all goes wrong when Jackie finds a picture of Rose. She tells him that she will not betray Rose or the Doctor. This angers Victor. Tensions are mounting, especially as two people have already disappeared, and Elton, Ursula and Mr. Skinner walk out, although Victor asks Mr. Skinner to stay behind.
Ursula, realising she has left her mobile behind, goes back with Elton, and sees Victor Kennedy's true form: a green creature with claws that absorbs people for knowledge. Although he doesn't say his name Elton thinks of him as an 'abzorbaloff' and the term sticks. Ursula is absorbed by the abzorbaloff, and he chases Elton into a cul-de-sac.
As the abzorbaloff is about to strike the TARDIS appears, and the Doctor emerges and stands to one side as Rose storms out and shouts at Elton. Both ignore the abzorbaloff until Elton points it out. Rose thinks it looks like a Slitheen. When the Doctor asks the abzorbaloff says he comes from Raxacoricofallaptorius's twin planet Klom.
The Doctor appeals to the previously absorbed people who start to pull, causing the abzorbaloff pain. It drops its cane, and the absorbed Ursula tells Elton to break it. The abzorbaloff''s limiting field is broken, and it melts into a green slime.
The Doctor explains to Elton about his first visit, and helps Elton one last time: He is able to capture the spirit of the last absorbed person in a pavement slab. Elton and Ursula can, in a fashion,. be together.