Botanist Silas strays into a forbidden forest and is implanted with a living root by Ilowyn, an ancient tree spirit imprisoned for three centuries—he cannot stray more than fifty paces away, or the root will drain his breath in seven seconds. This is no curse, but parasitism. Silas's birthmark, which only Ilowyn's sap can make glow silver, is the sole key to breaking the seal—or killing him. Daily spraying, licking, and vine-binding become a deadly erotic game as feelings grow. When their old master awakens to drag them back into the seal, golden roots of Ilowyn begin to sprout inside Silas.