One night, for no apparent reason, a vast and ancient forest appeared across the land as if it had existed there for hundreds of years. Destructively superimposed on all that existed before it, the forest devastated the works of man. Nothing escaped the blanketing of the trees, not even the tarmac of the roads or the buildings of the city centres. Life as we know it ceased: structures collapsed; roads, rail lines and runways were choked; and anything that may have helped with a swift recovery was lost. For a short while a state of emergency was broadcast over all available media, but soon these reassuring words fell silent. As devastating as the Event was, much worse was to follow.

It became apparent that this forest, soon to be named the Sea of Leaves, was not like any ordinary, mundane wood. Ancient, foreboding and somehow alive, it was a wild place, full of cunning, dangerous animals, and permeated by the Call, a siren-song, a lure that sucked the weak-minded, the desperate and the lonely into its depths. Within weeks over eighty per cent of people succumbed to the Call and entered the depths of the wood, never returning. Those that remained clung together however and wherever they could, slowly forming close-knit communities in locations that could be protected from the dangers of the wood.