The Walking Dead has become a phenomenon. A gritty drama that happens to be set after the zombie apocalypse. But it's not just the gory horror that people have latched onto, it's the human moments that give the show depth. The undead threat heightens the tension and exaggerates the character's relationships. Just don't get too fond of any actors as they are only one bite, bullet or blade away from death. '[Director and original show runner of season one] Frank Darabont … was instrumental in identifying that there was a niche market that hadn't been explored on television and he decided to write something that I had never read before, where the first episode was like a silent movie,' explains Andrew Lincoln who plays ex-cop Rick Grimes the de facto leader of our ragtag band of survivors. 'I had never read a pilot quite like it.'

Lincoln is also quick to praise Robert Kirman's comics that formed the basis for the show. 'He has written source material that has lasted for over 12 years now and which continues to have a voracious market. So that obviously has good storytelling — to be able to hold a very savvy readership.'

Lincoln has grown into Rick Grimes. Any memories of Egg in This Life or Simon in Teachers have been washed away in viewer's minds by the blood and violence of The Walking Dead. 'The people I trained with at RADA think it is hilarious; I am classically trained and yet I wear cowboy boots and a Stetson and I shoot zombies for a living.' The character has been on a huge journey fighting tooth and claw to protect his life and family. 'He has changed enormously since the first guy that I woke up with in the hospital [in the very first episode of season 1]. And that is one of the enduring appeals of playing the part; their environment forms these people. Is it nature or is it nurture? That is the eternal question that is thrown into this crucible.'

Season six was perhaps the most gruelling yet. It started with a ray of hope, with Rick and co finding apparent safety in the small town of Alexandria. For the first time in a long time they dared to dream about the future. The walkers continue to circle but it was the introduction of Negan (Jeffrey Dean Morgan) and his band of 'Saviors' that were the biggest danger. The second half in particular explored themes of moral corruption, the fine line between good and evil, highlighted by Morgan's (Lennie James) pacifistic stance against the ongoing bloodshed.

It all lead up to perhaps the biggest cliffhanger of any modern TV show. Obviously no-one is willing to spill the beans but we do know one of our heroes is about to die. But who? Comics fans might think they already know, but while the TV adaptation roughly follows the same structure, in many aspects it differs wildly from the source material (various characters who are dead in the comics are still alive on the show, and vice versa). 'We leave the show in a certain place and we do something that we have never done before. When I read it, it shocked me to the core.'

The Walking Dead: The Complete Sixth Season is available on Blu-ray™ and DVD from Mon 26 Sept (Entertainment One).