A city-wide blackout sends the hospital into total darkness. Bash treats a rock climber who fell from a cliff. Dr. Bishop and Bash make a major career decision, putting their futures on the line together. June is finally forced to face her father. Theo goes above and beyond to treat a deaf child, while letting frustration get the best of his spiralling personal life. Claire struggles to find footing in her new role as a nurse practitioner, and Mags pays a visit to a former mentor.

Bash's career is threatened, leaving him with a major decision to make. When a toxic father needs a liver transplant, Bash deals with the man's estranged son. While treating a woman having strange reactions to a spider bite, Mags employs a strategy to work alongside Novak. Theo helps a young lupus patient make her dreams come true, and takes steps to rebuild his life. June discovers her father's secret. Dr. Bishop and Claire begin a new chapter.