Skaro - The Dead Planet: A brief history of the Daleks

 was an internal document written by Philip Segal which outlined the initial idea for the Spider Daleks and their place within the Doctor Who universe continuity. It would inform the Leekley Bible, being meant to explain the Daleks to the non-fan John Leekley (however, Leekley was ultimately more inspired to retell Genesis of the Daleks than use it as backstory).

The document was reprinted for public reading alongside The Chronicles of Doctor Who? as a feature in Doctor Who: Regeneration. Beyond introducing the Spider-Daleks, it also possibly explains Segal's perspective on how Skaro reappears in the movie which he eventually produced and outlines the idea of a "Dalek Hive" which would reappear in Fire and Brimstone alongside the Spider-Daleks. Additionally, the document further explained the link between the Spider-Daleks and the 1960s Silver Daleks seen in concept art and the CGI test footage

Contents
The bulk of the document is a history of the Daleks. On Skaro, "the twelfth planet in a solar system not too far from Earth", Davros creates the Daleks in the aftermath of the neutronic wars. The events of Genesis of the Daleks are summarized. Davros then survives an assassination attempt and secretly flees to Nekros, where he lives through the backstory of Revelation of the Daleks and creates the Imperial Daleks. Segal's proposed Dalek story happens 300 years after the end of the neutronic wars, when the Spider-Daleks are operating on Skaro. Segal notes that "according to the record" Daleks invade Earth sometime in the future, which could be used to open their show's second season. Segal then says that "it is also known" that, after the events of Segal and Leekley's story, Skaro is attacked by an "invasion force" and the Daleks are though destroyed. Survivors of this invasion locate Davros and take him prisoner on Skaro II. Then, "sometime between the 32nd and 38th centuries," the Daleks restore Skaro to its glory after a period of inaction. Through taranium they are "once again" able to make time machines, and their first mission is to kill the First Doctor in The Chase.

The document's final section details Skaro's look. Segal emphasizes that Skaro is still recovering from the neutronic wars. Since the Spider-Daleks don't have as many problems of mobility, they don't need flat surfaces, meaning their structures can be like ant hills or hives. Segal stresses that an insect-like hierarchy of drones operating under a Dalek monarch will look powerful, making the Daleks desirable to the Master.