Rose has written a letter to her mum, which considering the tale she relates isn't very surprising. The Doctor had decided to take up stamp collecting; not the most exciting of past times recalls Rose, remembering a boy she went to Jericho Junior School with, Freddy or Frankie was his name. Anyway, Bath in 1840 is where the Doctor takes Rose to the printing place of the very first stamp – the Penny Black, the brain child of Rowland Hill who for the first time suggested a one price stamp for all any area in the country that the person sending the letter had to pay! (Up until then you paid to receive a letter and the cost depended on how far it had travelled).
On arriving at the printing place they soon find a man dead upside down in a barrel of black ink and are forced to hide in a backroom when a gang of printers, their Victorian suits covered in ink, give chase. In a room full of sheets with tiny pictures of Queen Victoria, looking some forty years younger than when Rose met her, and hiding in a corner is Thomas Scott. Thomas was a print operator whose job involved pulling a lever and making the impression on the paper while others (like those outside the room), were responsible for feeding in the ink and removing any excess. Thomas appears to be under some form of hypnosis which the Doctor manages to break using an old watch on a chain from his pocket.
Matching the description of a "large yellow monster with huge purple eyes" to a description of a Hobothy, the Doctor works out that the Hobothy (master hypnotists who channel their influence through another medium) are planning to exert their influence over millions exposed to the ink used in the stamp, like the print workers, with an embedded command to kill. As the door is broken down and the inked workers close in, the Hobothy appears and struck by Rose in the stomach falls back onto the press which Thomas instinctively pulls the lever on, squashing it between the press and paper, and besides ending the ink's influence over people creates a spoiled sheet of stamps tainted with a purple and yellow colouring. The spoiled stamps are all destroyed bar one which Rose sends her mum (remembering that misprinted stamps are often more valuable), and uses on the letter which the Doctor posted for her.
- References are made to Rose's previous travels with the Doctor with mention of: Raxacoricofallapatorius and zombies (referencing the Gelth), and the Tenth Doctor has a watch on a chain that he uses to de-hypnotise the print operator Thomas Scott.
- Rose Tyler also attended Jericho Street Junior School and had a cousin Mo who lived in the Peak District.
- The original short prose fiction featured in the Doctor Who Files series of hardbacks from BBC Children's Books was officially sanctioned by the Doctor Who production office.
- The description of the Doctor's appearance in this story is vague. However, Rose writes that she met Queen Victoria before, referencing the events of the Tenth Doctor television story Tooth and Claw.