London Under Siege is a high-concept, character-driven series set in a flooded, near-future London. When rising waters reveal an ancient network beneath the Thames, sixteen-year-old Alex Mendoza learns he is the last descendant of an oceanic civilisation built to keep balance between land and sea.

As governments scramble for control and rogue factions in the deep rise to reclaim the surface, Alex, Olivia, and Tom become the only link between two worlds on the brink of collapse. It’s a sweeping story of myth and climate, power and identity - where the storm is alive, the sea remembers, and one boy stands at the centre of the planet’s reckoning.