Martin Stowe and Sheila have been receiving offensive emails and telephone calls lately, and they suspect their co-worker, Indira. She claims to have received similar emails and calls, but at first they don't believe her.
The Doctor and Romana enter the estate office and ask Martin if strange things have been happening, and when he replies with a yes, the Doctor states he is here to help.
The emails and calls have included personal information, and they have been sent by different names. While the two women seem ready to accept the Doctor's help, Martin thinks he doesn't need the Doctor's help to save the Earth.
When the Doctor receives an email, he recognises that the name is a Glarn one. Martin tries to read the message, which has devastated the Doctor. Meanwhile, Romana explains that the Glarn are tacticians who provoke species into "wiping themselves out", after which the Glarn move in and take over the planet. Their intent is for humans to destroy themselves, and what the three estate agents have been experiencing is a test run.
Martin decides he can save the Earth himself and makes a suggestion, which the Doctor rejects. The Doctor explains that the Glarn don't invade, they use people's fears to provoke aggression.
Meanwhile, Martin sneaks a glance at the Doctor's email, which accuses him of being responsible for several deaths. Now Martin trusts the Doctor even less. After some arguing, they all face their biggest fears. Martin fears that he's not as much of a "hotshot" as he thinks he is.
Once they have faced their fears, they put the Doctor's plan into action. They send out funny and/or risqué texts and emails to their friends and families, which the Doctor says the Glarn can't handle. They receive many replies, all positive. Romana can no longer detect Glarn activity around Earth.
Once the Doctor and Romana leave, Martin is ready to go to the pub.
- The Doctor mentions Daleks, the Macra, Amelia Rumford and Tara. Romana mentions the White Guardian, the Taran wood beast and the Key to Time.
- K9 is in the TARDIS.
- Martin's mum used to make him watch Gone With the Wind.
- Martin's brother used to always say, "Carpe diem".
- Romana mentions Cybermen and Nestenes.
- The Doctor says the messages couldn't be from Mars.
- Haversock Laing is a rival estate agency.
- This story was reprinted in Short Trips: Re:Collections.
- The list of dead names associated with the Doctor include Temmosus, (TV: The Daleks) Katarina, Bret Vyon, Sara Kingdom, (TV: The Daleks' Master Plan) Edward Waterfield, (TV: The Evil of the Daleks) Toberman, Viner, (TV: The Tomb of the Cybermen) Gemma Corwyn, (TV: The Wheel in Space) Shura, (TV: Day of the Daleks) Aggedor, (TV: The Monster of Peladon) Professor Clegg, (TV: Planet of the Spiders) Rogin, (TV: The Ark in Space) Ronson, (TV: Genesis of the Daleks) Laurence Scarman (TV: Pyramids of Mars) and James Skinsale. (TV: Horror of Fang Rock)
- The Doctor and Romana are searching for the fifth segment of the Key to Time. (TV: The Power of Kroll)