Westworld season 2 episode 4 review: Peter Mullan strong contender for a supporting actor Emmy in pleasingly focused episode

"Is this...now?" a disorientated Bernard asks Elsie in 'The Riddle of the Sphinx', mirroring this viewer's confusion upon returning to Westworld each week to find the timelines increasing in volume and moving bafflingly closer together.

It was another intricate, information-heavy episode this week, but easily the season's best, giving us a welcome break from Dolores' megalomania and Maeve's surgical sassiness and focusing almost exclusively on the exploits of Williams young and old. The big reveal was that Delos had its sights on something even bigger than creating life-like robots: achieving immortality for humans by replicating their minds in the bodies of robots.

This unfurled nicely through the scenes with James Delos in the luxury apartment-cum-panopticon, which were rich with imagery, my personal favourite being the fact that he was pedalling backwards on the cycle machine ("you still don't understand the real game we're playing here, if you're looking forward you're looking in the wrong direction") during the storyline's pure horror conclusion. Peter Mullan injected some much-needed personality into the show this season and was on terrific form in this episode - presumably his last - his convulsions and stammers as his synthetic brain rejected its new body seeming painful human somehow and very hard to watch.

The capsule nature of this account of an experiment gone wrong and the closure that came with it was very welcome, especially since Bernard's storyline continued to throw up more questions than answers. "I think I know why Ford sent me here; he had me print a control unit for someone else, another human," is the line that will have fans theorising endlessly, and the candidates for this mystery 'human host' and the motives for Ford creating them are endless.

The answers may lie in the episode's denouement, however, which saw old William encounter his daughter Grace who we met in Rajworld. It feels likely that Ford wanted to show William that one can indeed transcend the "cognitive plateau" and successfully turn a human into a host just to show him why one shouldn't. Did he create another Grace? Another William? Resurrect their dead mother/wife who killed herself, Juliet? Given critics' previews have been cut off after next week's instalments, I wouldn't be surprised if we finally start getting answers in episode 6.

Westworld continues on HBO in the US and through Sky Atlantic and NOW TV in the UK.