Tensions rise as Celeste confronts Clara for failing to notice a missing first-class passenger before takeoff, recalling a past fiasco caused by a similar oversight. Despite the strict protocol, a doctor urgently needs to board carrying a donor heart for a critical transplant, forcing the crew to consider reopening the plane door mid-boarding. Celeste wrestles with the risk of delay and the potential fallout but faces pressure to prioritize the life-saving mission. Meanwhile, Ethan’s unexpected decision to take off despite the unresolved boarding issue leaves everyone stunned, prompting urgent questions about who will bear responsibility.