like the original series, stories often flowed directly into one another or were linked together in some way. Notably, in common only with the seventh and twenty-sixth seasons of the original series, every story of the season takes place on or near Earth. This fact is directly addressed in the original novel The Monsters Inside, in which Rose and the Doctor joke about the fact that all their adventures to date have taken place on Earth or on neighbouring space stations. The stories of the series varied quite significantly in tone, with the production team showcasing the various genres inhabited by Doctor Who over the years. Examples include the "pseudo-historical" story "The Unquiet Dead"; the far-future whodunnit of "The End of the World"; Earthbound alien invasion stories in "Rose" and "Aliens of London"/"World War Three"; "base under siege" in "Dalek"; and horror in "The Empty Child". Even the spin-off media were represented, with "Dalek" taking elements from writer Rob Shearman's own audio play Jubilee and the emotional content of Paul Cornell's "Father's Day" drawing on the tone of Cornell's novels in the Virgin New Adventures line. Davies had asked both Shearman and Cornell to write their scripts with those respective styles in mind. The episode "Boom Town" included a reference to the novel The Monsters Inside, becoming the first episode to acknowledge (albeit in a subtle way) spin-off fiction. Music Murray Gold composed the music for this series, which was entirely synthesised. Filming Principal photography for the series began on 18 July 2004 on location in Cardiff for "Rose". The series was filmed across South East Wales, mostly in or around Cardiff. Each episode took about two weeks to film. The start of filming created stress among the production team because of unseen circumstances: several scenes from the first block had to be re-shot because the original footage was unusable; the Slitheen prosthetics for "Aliens of London", "World War Three", and "Boom Town" were noticeably different from their computer-generated counterparts; and, most notably, the BBC came to a gridlock with the Terry Nation estate to secure the Daleks for the sixth episode of the series, to be written by Rob Shearman. After the first production block, which Davies described as "hitting a brick wall", the show's production was markedly eased as the crew familiarised themselves. Filming concluded on 23 March 2005. David Tennant, who was cast as Eccleston's replacement, recorded