Silo (2023)

If the Swan hatch was your favourite Lost discovery, Silo is an entire series set inside one. Thousands of people live in a vast underground tower, forbidden to ask what lies outside, and Rebecca Ferguson's engineer starts pulling at the rules. The place itself is the mystery: every level, stairwell and banned relic hints at who built it and why. This one is built to pay off. It adapts Hugh Howey's completed book trilogy, the third season aired from July to September 2026, and Apple TV has dated the fourth and final season for 9 July 2027.