After six months at sea on her first operational deployment, HMS Queen Elizabeth departs the Pacific for the long voyage home. Although it will be two months before the ship arrives back in Portsmouth, most are already thinking of family and Christmas. As the ship makes its way across the Indian Ocean, the F35 jet pilots have to maintain a strict round-the-clock programme of launches and landings to ensure combat readiness - until, one morning, an F35 on a routine launch loses power at a critical moment.