Westworld - a theme park where guests indulge fantasies with robots, a destination offering the future of sin, the artificial intelligence that fuels it and the humans that sense there's something more sinister at play.

When a chance encounter brings soldier John Watson into Sherlock's life, it's apparent the two men couldn't be more different, but Sherlock's intellect coupled with John's pragmatism soon forges an unbreakable alliance as they investigate a series of baffling cases together.

Sherlock is back, but will things ever be the same again?