Harmony Cobel / Mrs. Selvig

Harmony Cobel runs the severed floor at Lumon as Mark's manager, a woman of clipped rituals and unsettling devotion to the company's founder. Outside work she appears as Mrs. Selvig, Mark's oddball neighbor, watching him with an attention that seems more than neighborly. She is precise, controlling, and quietly obsessive.

Arquette plays Cobel as two people who never quite match up: the brittle corporate zealot and the frumpy neighbor, each performance slightly too intense for its context. That mismatch is the character's engine — you sense a private agenda humming beneath her devotion to Lumon long before the show explains it, and Arquette never lets you see the seams.