The Third Day, kendini gizemli bir adada bulan Sam'in maceralarını işliyor. Sam zamanla adadaki ayinlere dâhil olurken gerçeklikle hayal dünyası arasındaki sınırlar ortadan kalkar.
Chronicles the individual journeys of a man and woman who arrive on a mysterious island at different times. The story is told over six episodes in two distinct halves. "Summer", directed by Marc Munden (Utopia (2013), National Treasure (2016), sees Sam (Jude Law), a man drawn to a mysterious island off the British coast where he encounters a group of islanders set on preserving their traditions at any cost. "Winter", directed by Philippa Lowthorpe (Three Girls (2017), Swallows and Amazons (2016)), follows Helen (Naomie Harris), a strong-willed outsider who comes to the island seeking answers, but whose arrival precipitates a fractious battle to decide its fate. On it's first broadcast in the UK, placed between "Summer" and "Winter" is a separate immersive live-event called "Autumn"