Reread 2011. Dômeki frees Watanuki's arm from a spider's web, incurring the spider's wrath; Watanuki sacrifices his right eye to save Dômeki. (It's CLAMP: it's not true love until someone loses an eye.) A photograph reveals a murderer's soul. Dômeki is desperate to restore Watanuki's eye. A bookworm eats words.
The series has hit its stride: even the one-offs seem less annoying and have more interesting twists or imagery than they did in Volume 1. Sometimes they even key into the character arcs for the main characters, although I'm not sure the murderer does here.