The monster is a CGI creation from The Mill, based on [Stephen]Greenhorn's notes, but what they dreamt up astonished the writer. "I'd written a bit about the scientific theory behind where this monster comes from, and a vague idea of how I thought it might look," says Greenhorn. "The guys at The Mill saw that and thought, 'We can do better than that!' They regard themselves as the torch-holders of 'behind-the-sofa' moments - and they reckon this is one of the scariest things they've done."

6. Monsters Inc. - An episode of Doctor Who just wouldn't be the same without a monster to scare the living daylights out of you!

The creation of such a beast is never easy - especially when it's purely computer generated!

Confidential is on set throughout this chilling episode, spends some quality time with guest star Mark Gatiss and takes a look at some of the fantastic prosthetic and computer generated monsters created since the series made its welcomed come-back in 2005.

7. Space Craft - It's back into outer space for Doctor Who and this time it's an adventure set entirely on a spaceship.

Join Confidential as we gain exclusive access to Doctor Who's art department and take you on a tour of the spaceship's sets and locations. Confidential also journeys back in time to show you some of the best off the wall spaceship designs seen in five decades.

Guest star Michelle Collins discusses her role as the ship's captain, and how she felt performing stunts on her very first day on set.

From models on wires to cutting edge CGI, this is a space craft extravaganza.

8.Alter Ego - With aliens in hot pursuit, the Doctor and Martha find themselves in 1913 England.

Confidential is right beside them to delve deeper into the alter ego of the nation's favourite Time Lord.

Amidst all the stiff upper lips, we follow the advancing 'aliens' and their army, with exclusive backstage footage of the mayhem caused as the outer-space enemies close in on their prey.

Filmed almost entirely on location, Confidential was on-set with cast and crew in the winter wind, rain and mud for the nail-biting first episode of this two-part story.

Features interviews with writer Paul Cornell, whose original novel forms the basis of Human Nature, David Tennant and Freema Agyeman.

9. Family Ties - With The Family of Blood breathing down the neck of the Doctor, time is running out.

Confidential follows the action backstage as we glimpse a life more ordinary (for the Doctor) as well as a vision of the dark future ahead.

The complexities of filming this powerful episode are revealed, as well as the logistics behind the explosive ending.

Features interviews with head writer, Russell T Davies and Freema Aygeman on one of her toughest TARDIS assignments yet.

10. Do you remember the first time? - This week, David Tennant directs his very own Doctor Who Confidential. TV's top Time Lord has been given complete control to film his own very personal account of the making of Doctor Who and to take a nostalgic voyage of discovery to find out the secret behind the success of Doctor Who.

In this unique piece of television, David roams around the BBC, talking to cast and crew and fans of the show, uncovering the secret behind the success of Doctor Who.

From BBC bosses through to the Dead Ringers team, David is hunting for what makes Doctor Who so magical. He chats to the Daleks in the Blue Peter Garden, and discusses with Mark Gatiss the joy of playing a Doctor Who monster in the Lazarus Experiment.

Head writer, Russell T Davies and producer, Phil Collinson chat with David about how they've always had such fondness for the show and how it inspired their creative drive. Executive producer Julie Gardner and drama commissioner Jane Tranter reveal how and why the series was brought back and the unprecedented response it's had.

Stephen Moffat joins David on a hunt around Television Centre, looking for the studios where the classic series was filmed. They end up on the set of Newsnight.

Confidential also features exclusive backstage footage of Blink; one of the scariest episodes to date and candid chats with two of the week's most prominent stars, Carey Mulligan and Finlay Robertson who talk to David about their experience working on the show and on becoming part of the Doctor Who legacy.