Sasha Lane plays Bobbi, the ex-girlfriend to Alison Oliver's Frances.
Jemima Kirke plays Melissa, a journalist who is married to Joe Alwyn's Nick.
Over time, Nick and Frances' relationship turns romantic, threatening the friendship established between the group.
Frances is torn by her love for Bobbi and the future she could have with Nick, who is not entirely happy in his marriage to Melissa.
Though the show is similar in style to Normal People, director Lenny Abrahamson told Vanity Fair, "What we've ended up with is something that has a kind of aesthetic family resemblance to the other series, but is definitely its own thing."
The series is based on Sally Rooney's first novel of the same title.