A painter's life is forever changed when a mythical and deadly spirit from Celtic lore – a Leannán Sí – becomes his muse and lover. A painter's life is forever changed when a mythical and deadly spirit from Celtic lore – a Leannán Sí – becomes his muse and lover. A painter's life is forever changed when a mythical and deadly spirit from Celtic lore – a Leannán Sí – becomes his muse and lover. A painter's life is forever changed when a mythical and deadly spirit from Celtic lore – a Leannán Sí – becomes his muse and lover.