I'm watching this on Kodi so not sure can watch it in the UK. It's a ten-parter, three episodes in.
If anyone has read the book, the series is equally if not more chilling. It stars Penn Badgely as Joe; the psychopathic narrator and obsessive stalker.
The story is horrific but at the same time written so well it allows the reader/viewer to understand why the stalker believes the fantasies.