Kit and Mina’s hopes of entering the prehistoric doorway to the Spirit Well have been thwarted. Their shadow lamps lie destroyed. Regrouping with their fellow questers in Mina’s sixteenth-century coffee house, they determine to find another way through. When one of their own disappears with Sir Henry’s cryptic green book, they no longer know whom to trust. Without the mysterious ingredient which drives the shadow lamps, with key pieces of the map still missing, and with the evil Lord Burleigh still on their tails, the way forward remains elusive.