As the fifth season of BBC’s Luther concluded, the British TV juggernaut has released the complete footage of all five of the seasons. Idris Elba has bulled his way through an onslaught of evil – some close to his heart, some within his heart – and for nine years we were held captivated by the adventures of his Detective Chief Inspector John Luther. And now? Now, we wait.

While the show is incredibly exciting (and dark in a way that few shows have achieved, sustainably), it is ultimately a character study of Luther: what makes him tick? How can he determine right from wrong? Where are the places where grace is available even in the dark? How much brutality can one human being be expected to accept?

It happened nine years ago so it hardly seems like a spoiler to point out that some of the darkness is induced by Luther himself, but much of it comes from the outside – including the murder of his ex-wife Zoe who he still loved. How does someone who has dedicated his life to stopping violence deal with the violence hitting that close to home? Who can he become and what hope can he possibly have?

Weirdly enough, Luther’s support comes from within the police department – and from serial killer Alice Morgan (the deliciously devious Ruth Wilson). This is the genius of Neil Cross – that good and evil are a dance in the dark, and that defeating evil requires good to sacrifice something in the process. The evil on the outside is brutal in each of the cases Luther tackles, but it’s a reflection of the wolf within him that he constantly fights to control.

For fans of the show, there are several extra features – “The World of a True Maverick,” “Lust for Luther,” etc. that take us into Cross’ world for Luther and allow us to see more. But watching the series in its entirety will leave you breathless still as the credits roll at the end of season five, with only one question:

How long must we wait for the Luther movie?