Baby Reindeer tells an intimately personal story already explored by the show’s writer, Scottish comedian Richard Gadd, in a couple of acclaimed one-man Festival Fringe shows. It follows a depressed Scottish barman called Donny, played by Gadd, as he becomes enmeshed in the life of a female customer, “Martha Scott,” who is stalking him, sending him more than 41,000 emails, 350 hours of voicemail, 744 tweets, 46 Facebook messages, 106 pages of letters and torpedoing his other relationships. The show was meant to be a close-up, complex—even funny—look at mental health problems and the way sufferers can feed on each other’s different illnesses. According to its millions of fans worldwide, the Netflix drama, which shot to the streamer’s No. 1 slot, achieved these tricky goals. But as determined social-media sleuths attempt to identify the actual people the characters are based on, Baby Reindeer is also now likely to change how fictionalized crime is seen. —Vanessa Thorpe