Dr Smith shelf

The Dr Smith shelf, sometimes known as simply the Shelf or (jokingly) as Dr Smith, was a special shelf in P.R.O.B.E. HQ, where P.R.O.B.E. kept some of their most important alien items and documents.

Nature
The items on the shelf, which were not to be removed from it by anyone except in the case of a triple-Z-class emergency, were generally objects which had been given to P.R.O.B.E. by "nonhumans... time-active ones". Many had no apparent purpose, but P.R.O.B.E. believed that they would become useful at a specific future date, as part of various time travel gambits. (PROSE: Out of the Box) The shelf was named after an old associate of Liz's, "Doctor John Smith", (HOMEVID: When to Die) an alias used by the Third Doctor during his work with Liz at UNIT. (TV: Spearhead from Space, etc.) The name was a mystery to later members of the P.R.O.B.E. team, who knew that no "Doctor Smith" had ever worked for P.R.O.B.E.; they came to the joking conclusion that "Dr Smith" was the name of the shelf itself. (PROSE: Out of the Box)

Contents
Shortly after an inactive Box was gifted to her, Liz placed her on the Dr Smith shelf because she wasn't working properly. Giles found her there in 2014 and took her off the shelf, successfully repairing and activating her, but after being broken by the exploding Paul Reynish, (HOMEVID: When to Die) Giles placed the broken Box back on the shelf once again, where she remained until 2019, with brief interludes when she was removed so that Giles or someone else could take yet another shot at repairing her.

Other items on the shelf by 2019 included a longsword (PROSE: Out of the Box) belonging to the ghostly Sir Bedevere, (PROSE: Preternatural Nights) a teddy bear, a jar of sealing wax which a post-it note claimed would become useful in 2076, a Gonzie data-masticator, a "bootleg quantum communicator", and a sentient Sun Builder weapon called the Greater Key, (PROSE: Out of the Box) a relic of the War in Heaven. (PROSE: A Farewell to Arms)

The shelf was also home to a number of documents and books. They included Beyond a Boundary: The Incomplete History of Cricket in the British Isles by Robert L. C. James, A Memoir on the Martian Invasion of Earth by H. G. Wells, B. S. Ghast's Compendium on Ghost Physics, a complete collection of Noddy books which a note marked out as "very important", and also a number of reports typed up by Giles himself. One of these was a report on "the dangers Chronon Fleas presented for archives", which was itself "gnawed at" by Chronon Fleas. (PROSE: Out of the Box)

History
In 2014, when Giles first looked through the contents of the Dr Smith shelf, it was located in one of P.R.O.B.E. HQ's out-of-the-way storage areas. He took Box from the shelf, where Liz had placed her many years earlier, and successfully reactivated her, though she was soon broken again, (HOMEVID: When to Die) after which Giles returned her to the shelf. (PROSE: Out of the Box)

By 2019, under Giles's leadership, the Dr Smith shelf had been moved to Giles's office within P.R.O.B.E. HQ. (PROSE: Preternatural Days) It became a subject of much gossip among the new members of the team. Eventually, Maxie spotted that Box was not quite inactive, and got Giles's authorisation to take her off the shelf to attempt to repair her, with Maxie eventually succeeding. (PROSE: Out of the Box) However, she was still returned to the shelf in-between missions. (PROSE: Preternatural Nights)

Information from invalid sources
The Dr Smith shelf once appeared in one of Giles's case files. At that time, the shelf contained a Cyberon head, a vial of Cyberon, and Box. (NOTVALID: P.R.O.B.E. CASE FILES - TRAILER)