Kabapu has spoken of a gate...Il Palazzo has spoken of a door. And for some time now, finding this portal has been the secret job description of the City Environmental Security Administration—secret, of course, from them most of all! Now Kabapu has made the task plain, but not plain enough to keep them from being trapped in ACROSS’s base with little food, little water, and a little problem called Elgala. And Umi, too, will journey deep into the mysteries that lie beneath Fukuoka...if that’s what it takes to save her friend Teriha...