
Black Mirror has always been an anthology show. Since the first season aired back in 2011, each season has consisted of entirely unrelated episodes, with no callbacks between seasons, either. Season 7 has changed all that, though.
Will Poulter's eccentric game designer Colin Ritman was a character in 2018's interactive Black Mirror movie, Bandersnatch, but that wasn't the last we'd seen of him, it turns out. He makes an appearance in the fourth episode of season 7, 'Plaything', when games journalist Cameron is invited to preview a mysterious new project that Colin has been working on at Tuckersoft.