The second series of British science fiction programme Doctor Who began on 25 December 2005 with the Christmas special "The Christmas Invasion". A regular series of thirteen episodes was broadcast weekly in 2006, starting with "New Earth" on 15 April and concluding with "Doomsday" on 8 July. In addition, two short special episodes were produced; a Children in Need special and an interactive episode, as well as thirteen minisodes titled Tardisodes. It is the second series of the revival of the show, and the twenty-eighth season overall.

Elisabeth Clara Heath-Sladen was an English actress. She became best known as Sarah Jane Smith in the British television series Doctor Who, appearing as a regular cast member from 1973 to 1976, alongside both Jon Pertwee and Tom Baker, and reprising the role many times in subsequent decades, both on Doctor Who and its spin-offs, K-9 and Company (1981) and The Sarah Jane Adventures (2007–2011).