The Woodhouse Nature Reserve in South East London is a sprawling hectare of knotted ivy and mossy tree stumps. And while its edges are speckled with rusting tins and damp takeaway boxes, its interior is verdant, untouched. There, beyond the padlocked gates some thing, some creature, is living. Peter and Carly both embark on their own quests to discover the truth behind sightings of this unknown animal. Their search will draw us back into a history of dreamers and hoaxers, as their ordinary lives are riven by a growing obsession with this fantastical story.