An excellent example of how lively and entertaining the McCoy era was. Despite some continuity problems this story is well scripted, well paced and well cast. Look out for Michael Sheard, playing the headmaster - he played Admiral Ozzel in Star Wars: The Empire Strikes Back and Hitler in Indiana Jones and the Last Crusade.

This story revolves around two different Dalek factions, the Imperial Daleks and the renegades, competing for the Hand of Omega, a stellar engineering device left back in 1963 by the Doctor before the events of the first Doctor Who adventure "An Unearthly Child". The Doctor and Ace, of course, find themselves in the thick of the action, along with a military task force and its conscripted scientific adviser.

The Daleks are in fine form, with some decent special effects and good action sequences. This story marks the introduction of their ability to finally ascend stairs. As with other McCoy stories there are hints that the Doctor is more than he appears to be, and some excellent dialogue between him and other characters. The underlying theme of racism is fairly subtle and well handled. There's a cute self-referential joke in episode one (pay attention to the TV set Ace switches on) and some nice twists in the story.

This DVD is chock full of extras, continuing the BBC's recent trend with Doctor Who releases. The extended and deleted scenes are a particularly worthwhile extra, with written explanations preceding each scenes... so much better than just stringing them all together without comment as on other Dr Who releases. Also of note are the out-takes.

There's a commentary with Sylvester McCoy and Sophie Aldred. Although entertaining enough, it's not exactly lively - but worth a listen anyway.