Luther is a psychological crime thriller featuring DCI John Luther, a brilliant detective whose passionate involvement in his work threatens to derail his personal life. Unlike any other drama each episode of this crime thriller opens by revealing a killer's identity.
Sorry, no info about the next episode of Luther is available yet.
However, our last information about it is this:
A day after Fox touted the development of a U.S. adaptation of British crime series "Luther", BBC America has announced that the original iteration of the drama will return for a two-part miniseries in 2015.