HBO Series 'Perry Mason' Adds 'Marriage Story' Actor Mark O’Brien

EXCLUSIVE: Actor and filmmaker Mark O’Brien is set to star in season 2 of HBO‘s Perry Mason in the recurring guest star role of Thomas Milligan.

Thomas is Los Angeles’ ambitious Deputy District Attorney. He’s described as an aggressive attack dog in court as he strives to make his mark and ascend to greater heights, no matter whose blood he has to spill to get there. Season 2 will be eight episodes long with Matthew Rhys returning to the title role in the Emmy-nominated series.

Season 2 of Perry Mason takes place months after the end of the Dodson trial. Perry (Rhys) has moved off the farm, ditched the milk truck, he’s even traded his leather jacket for a pressed suit. It’s the worst year of the Depression, and Perry and Della (Juliet Rylance) have set the firm on a safer path pursuing civil cases instead of the tumultuous work criminal cases entail. Unfortunately, there isn’t much work for Paul (Chris Chalk) in wills and contracts, so he’s been out on his own. An open-and-closed case overtakes the city of Los Angeles, and Perry’s pursuit of justice reveals that not everything is always as it seems. Also, Diarra Kilpatrick’s Clara has a new baby on her hands and has moved in with her brother’s family. She can feel the walls closing in, though she has her husband’s back amidst increasingly challenging dynamics at home.

Deadline announced the series’ new cast members with Katherine Waterston joining.

O’Brien will next be seen in AMC’s 61st Street, opposite Courtney B. Vance and Aunjanue Ellis. The series will debut this year.

He recently starred in Focus Features’ Blue Bayou opposite Justin Chon and Alicia Vikander.

O’Brien recently wrote and directed his first film The Righteous, which made its World Premiere at Fantasia Festival last August. He was nominated by the Directors Guild of Canada for Outstanding Directorial Achievement in Feature Film. Additionally, The Righteous won Best Screenplay and Best Cinematography at Grimmfest in the UK.

His other feature acting credits include Marriage Story, Arrival, Goalie, The Front Runner and Bad Times at the El Royale. In 2020, O’Brien won a Canadian Screen Award for the film Goalie. He is represented by is represented by UTA, Thruline Entertainment, The Characters Talent Agency, Narrative, and James Feldman.