Unlike everything outside of the Lost In Time box sets released a few years ago, The Invasion is a unique DVD release in that it’s a story with entire missing episodes. Parts one and four of this eight-part, ahead-of-its-time humdinger of a Cybermen story are missing from the BBC’s archives. Having worked with animation studio Cosgrove Hall (of Danger Mouse fame) on the web-based 2003 adventure Scream Of The Shalka, the BBC engaged their services once more with a much more difficult assignment. This time, Cosgrove Hall would be replacing two entire 25-minute episodes of a well-regarded classic Doctor Who serial…and though the two episodes were missing, enough reference material survived (to say nothing of the other six parts of the story) that die-hard fans would know what the missing segments should look like. Even for one of the most renowned animation studios in the UK, this was a high-profile, high-pressure assignment – especially since one of the missing episodes was the opening chapter of this story and would therefore be the very first thing seen on the DVD. (more…)

Promoted as the test subject for an upcoming line of somewhat more streamlined (in terms of bonus features) classic Doctor Who DVDs, The Sontaran Experiment is pretty unique – it’s the only two-part story in Tom Baker’s era, and one of the only ones featuring location work shot on video instead of film. (The entire story is shot on location, so while much is made of this point by students of the show’s history, I’m not entirely sure that it really mattered, since it would’ve been either all-video or all-film anyway.) With only two 25-minute episodes, this Experiment is not unlike the Sontarans themselves: short, to the point, and with little in the way of frills. (more…)