Mark and his sister Devon collaborate with Harmony Cobel to uncover Lumon's secrets, aiming to rescue Gemma. Simultaneously, Helly delves deeper into Lumon's mysteries, while Irving faces a poignant farewell with Burt, departing Kier with his dog, Radar. Tensions escalate as Dylan confronts personal turmoil, and Milchick's loyalty to Lumon wavers under Drummond's oppressive oversight.