Lilly Stone is a brilliant, perfectionist architect whose life ends abruptly in a tragic accident at a cathedral on her wedding day. However, instead of passing on, Lilly finds herself trapped in "The Gray"-a digital and ethereal purgatory that exists between the world of the living and the Great Afterlife.Lilly discovers that her fianc , Allen, and her former firm are moving forward with her final masterpiece: a revolutionary glass greenhouse in Miami. However, the blueprints are flawed. From the Gray, Lilly realizes that if the building is constructed as designed, it will eventually collapse, potentially killing Allen.