Near the remote village of San Ferna in the Andes, an ancient beech tree is about to be cut down to make way for a highway, but old man Armando protests that it protects the village. Jack receives a telephone request from Andrew, a boy whose brother Lawrence has plants beginning to sprout from his body. Jack and Pinoko travel to the outskirts of London where he examines Lawrence, but finds no clinical explanation for the plant. That night Lawrence disappears and while Jack and Andrew search for him, he appears at Jack's hotel and takes Pinoko with him to the airport from where they fly to San Ferna. Jack and Andrew follow them and reach the boys' parents' house but Lawrence has not arrived. Meanwhile, Armando is camped near the ancient tree and he hears it tell him to find the children. Jack finally finds them, and after a thorough examination he finds that a seed from a beech tree, Fagus Sieboldii, has taken root within his body and is beginning to take control. Jack operates to remove the parasitic plant, and Lawrence begins to recover. On the day the ancient tree is to be felled, Lawrence arrives and sings to it. It flowers, then disperses its seeds before it withers and dies.