'The Last Day' by Steven Moffat

Arcadia, Gallifrey: A newly-recruited soldier is instructed in the use of his point-of-view Headcam implant, before taking up his station to scan the skies for any possible Dalek incursion. To the horror of his commanding officer, the soldier detects the impossible: a lone Dalek has somehow penetrated Gallifrey’s Skytrench defences. As sirens blare throughout the control room the two soldiers look on in terror as thousands more Daleks swoop down through the clouds. Flying straight towards Arcadia, the invaders open fire…

Chris Finch (Time Lord Soldier), Barry Aird (Older Time Lord Soldier), Alan Gill (Time Lord Soldier)

Directed by Jamie Stone
Produced by Denis Paul
Executive Producers Steven Moffat and Caroline Skinner
A BBC Wales production

Notes:
*This minisode does not feature any of the main characters from 'The Day of the Doctor', but does refer to another, related day...

*The clip was made available on iTunes from 20th November 2013, initially costing £2.49 in the United Kingdom store, and for free in the United States; however, the BBC quickly advised that it should be free of charge in the UK as well as the rest of the world, and iTunes were instructed to fix their error. The minisode was later released as an extra on the DVD and Blu-Ray of ‘The Day of the Doctor’.

*Working title: 'Doctor Who: WW Prequel'