One of the most popular story arcs from Doctor Who's "Fourth Doctor" period (starring Tom Baker as the Doctor), writer Terry Nation's Genesis of the Daleks not only fleshes out the back story of the Doctor's most fearsome nemeses--the megalomaniacal, robotic Daleks--but also serves up a thoughtful storyline that doesn't skimp on the action. First aired on the BBC in 1975, the six-episode story has the Doctor and companions Sarah Jane (Elisabeth Sladen) and Harry (Ian Marter) summoned to the Daleks' home planet of Skaros at a time prior to their rise to power. Hoping to prevent the domination-hungry beings from developing their warlike behavior, they soon find themselves in the middle of a war between two races, the Kaleds and the Thals, and uncover a plot by a Kaled scientist, Davros, to render his people invincible as the metal-encased Daleks. A gripping story with elements that remain topical even today (ancient cultures locked in an endless war, genetic experimentation, eugenics), Genesis of the Daleks is an excellent starting point for first-time Who viewers, and a fine reminder of the show at its best for longtime fans. The two-disc DVD offers a considerable amount of extras, most notably a commentary track by Baker, Sladen, co-star Peter Miles, and director David Maloney. "Genesis of a Classic" is an hour-long featurette about the story, with interviews from all the major (surviving) cast and crew members, while "The Dalek Tapes" explores the creatures' history via rare clips and interviews with performers and production staff. There's also a clip from a vintage episode of the U.K. children's series Blue Peter that's devoted to Doctor Who models and creatures, as well as the detailed photo gallery and subtitled text commentary that are standards on all Doctor Who DVDs. Those with DVD-ROM can access PDF documents of the 1976 Doctor Who Annual and listings from the Radio Times. --Paul Gaita