A wildlife volunteer on an uninhabited island off the British coast descends into a terrifying madness that challenges her grip on reality and pushes her into a living nightmare.

A wanderer drinks from an ancient well and is drawn into a celebration of the Winter Solstice, marking the year's turning at the earth's edge. Sense the stillness in the night, down by the sea, as the wanderer joins with the Guilds of Montol enacting the rituals and customs of distant ancestors to call back the sun.