Rick Mountcastle

Rick Mountcastle is a federal prosecutor working out of a modest office in rural Virginia, the kind of place OxyContin hit hardest and earliest. He's methodical and unflashy, more interested in building an airtight case than making noise, and he starts pulling at loose threads in Purdue Pharma's marketing practices with the patience of a man who expects the truth to take years to prove.

Sarsgaard plays him almost entirely through restraint — no righteous monologues, just a prosecutor quietly cataloguing lies until the pile becomes undeniable. That understatement is the point: against a pharmaceutical machine built on charm and spin, Mountcastle's dry, procedural doggedness feels like the only honest weapon in the room, and Sarsgaard makes watching him work oddly riveting.