Big Finish Productions releases the fourth U.N.I.T. audio drama, a Doctor Who audio spinoff. Nicholas Courtney and David Tennant guest star in what is intended to be a “season finale”, though it will be several years before Big Finish revisits U.N.I.T. as its own audio spinoff. 
The 711th episode of Doctor Who (the 13th since the series’ revival) airs on BBC1. The ninth Doctor regenerates, making him the second shortest-lived incarnation of the Time Lord (after Paul McGann); even Colin Baker outlasted Eccleston in the role. John Barrowman and Paterson Joseph guest star; David Tennant makes his first brief appearance as the tenth Doctor.