Very disappointing ... the plot is just so ridiculous and the Andy Serkis baddie so utterly unbelievable that even for Luther it's absurd. One minute serkis is an incredible fit and violent character ( with of course infinite resources and a complete knowledge of the underground tunnels in the London tube network) happy to take on and can beat a fully fit Luther in a hand to hand fight but later he runs away in fear from a tortured and near mortally wounded Luther. If you're a Luther fan, as I am, you'll probably watch it anyway just to see but be prepared to completely give up on all your critical faculties to make it watchable.