HBO is developing “We Are All Completely Beside Ourselves” as a miniseries with Marta Kauffman’s Okay Goodnight production company. The network has ordered a script based on the novel of the same name by Karen Joy Fowler, with Natalie Portman attached to star and executive produce alongside Kauffman.

The story centers on college student Rosemary Cooke (Portman), whose “twin sister” — actually a chimpanzee — disappeared when she was five years old, with her older brother following not long after. Christopher Monger (of HBO’s awards juggernaut “Temple Grandin”) will write the adaptation. Gideon Raff, co-creator of Showtime’s “Homeland,” is also attached as an executive producer, as is Okay Goodnight’s Robbie Tollin. Hanna KS Canter will co-produce.

Okay Goodnight is behind “Grace and Frankie,” starring Lily Tomlin and Jane Fonda. Tomlin is currently up for a lead comedy actress Emmy for the second season of the Netflix original, which premiered May 6 on the streaming service. Production on Season 3 will wrap in Los Angeles later this month.

Kauffman’s production shingle is also adapting Israeli family drama “Shtisel” for Amazon under the new title “Emmis.” Etan Cohen (“Tropic Thunder”) serves as executive producer, writer, and director for the pilot.

“These two projects demonstrate the range I envision for Okay Goodnight, and I couldn’t be happier to see them come to fruition,” Kauffman said in a statement.