Tarry is a vendor at the Farmers Market in New Orleans, a man who brings his produce to sell to the customers who stroll through the stalls and booths every Saturday morning. His are the best crabs, fishes, berries and other fruits available at the market, the most sought-after by the buyers, because he brings them directly from his home in the bayou. Tarry knows the plants' seasons and their currents of ripeness and readiness better than anyone else; he's unusual, a man with skin that acts as a plant-like organ, able to convert sunlight to energy, due to an experimental operation that saved his life as a youth, when an otherwise fatal illness was cured by the conversion. Millions of other people have had the same operation as well in subsequent years, the photosynthetic enhancement conversion; now they all can not only live off sunlight, but they can sense the messages that the plants share with one another, giving them insight into the lives and needs of plants. And the PSEs have become a culture all their own in the world, living together in the sunny cities of the world. Most of the PSEs have beautiful green skin, and they take pride in their color and their relationships with their botanical cousins. Tarry's skin is different though, because his early conversion process to become a PSE was an experimental one that was discontinued afterwards; his skin turned out to be a dull, dreary gray, and he is looked down upon as someone who is different, whose color doesn't fit in with the rest of society. One person chooses not to be put off by the gray skin. Anne Reed is a reporter for the New Orleans Commercial-Journal, one who happens upon Tarry's stall at the farmers market one Saturday morning. As they meet and talk about the goods he sells, an unlikely romance begins to develop between the two, despite the differences in their cultures and bodies. They're a case of opposites who attract, each pulling the other from their low-risk comfort zones, and showing each other how to live fuller lives, Anne learning to slow down and see the beauty of plant life, while Tarry learns that the society of people has an attractive side worth living in, despite the risks of dealing with human nature. But a dangerous new plague has emerged as a fatal threat to all the people whose skin consumes the sunlight, and Tarry falls victim to the disease. When Anne nurses Tarry through the illness, he becomes the target of the medical researchers who are racing to find a cure to the plague. His body becomes a potentially lucrative gold mine for the first lab that can figure out how to exploit his return to health to develop a cure that can be sold to millions of others around the world. Tarry and Anne are suddenly forced to flee from the people who are seeking his blood, and their race for freedom requires increasingly desperate measures to maintain Tarry's freedom as they try to find a way to both help solve the deadly plague while also maintaining his safety.