A former star of HBO’s controversial cult show Girls will guest star alongside Sherlock‘s Benedict Cumberbatch in Melrose on Sky Atlantic.

The upcoming drama is based on a series of semi-autobiographical novels by Edward St. Aubyn, and Allison Williams has joined the cast.

According to The Hollywood Reporter, the star of the critically acclaimed movie Get Out – who is best know for her role in oft-near-the-knuckle Lena Dunham series Girls – will join the five-part show for a single instalment. She will play Marianne, an acquaintance that Patrick (Cumberbatch) encounters during his playboy years in New York.

Already on the cast list for the Showtime/Sky Atlantic co-production are names such as Hugo Weaving (The Matrix), Jennifer Jason Leigh (Hateful 8) and Indira Varma (Game of Thrones). All, it appears, will make episodic appearances in a similar manner to Williams, as each distinct chapter mirrors one of the five books in St. Aubyn’s series.

All five adaptations will be handled by David Nicholls (Far From the Madding Crowd), and shot by Edward Berger (Deutchland 83, Jack).