Doctor Who's next mission on Saturday (BBC1, 7.30pm) sees the Time Lord and Clara teaming up with Robin Hood to try and save medieval England from the crazed Sheriff of Nottingham (played by Ben Miller).
There are plenty of amazing archery scenes and sword fights in the adventure - and in the midst of it all is Death In Paradise star Ben, who told What's On TV how he nearly took one sword fight a little too far.
"In the Sheriff's sword fight with Tom Riley, who plays Robin, I came at Tom like a bull in a china shop. I have this big thing about sword fighting in films in that it never looks like they're trying to hit one another. So I thought I'd genuinely try to chop his head off and hit him. Luckily Tom was very experienced with swords, so I knew he could handle a novice like me!"
"I hadn't done sword fighting before, as Tom Riley will attest to, because I think I actually created a new joint in his thumb during one of the fight scenes! He's a brilliant sword fighter so if I look good it's only because he's so brilliant."
Ben learnt plenty of new skills too, including archery. "I did have archery lessons," says Ben. "It was fantastic learning to fire a longbow."
He loved the Sheriff's outfit, too, which helped him enormously to get into the villainous role. "I wanted to make my Sheriff as evil and dark as possible, which was so easy when I was dressed up in his amazing costume and sporting a beard. It's my first time ever playing a baddie, and it was such fun, much more fun than being a goodie. Sadly I can't keep the costume. I was told it's going straight into a museum in Cardiff."
Just as menacing, too, are some new Doctor Who monsters who are controlled by the Sheriff from his castle.
"The killer robot knights are very scary and disturbing, especially with their Darth Vader-like voices! Doctor Who is always great at throwing up oddly frightening new monsters like this. I'm hoping kids will run behind the sofa when they see me as the Sheriff with his knights!"
