Flowers are reviled and despised in the land of the trolls. An ugly but unconventionally-friendly troll lives in the kingdom and, with his magical abilities, grows one flower too many for the Queen of the land, Gnorga, whose laws require all trolls to act mean and to scare outsiders whenever possible, lest they be turned to stone. As a punishment with convincing, he is intended to be exiled to a world devoid of plants, where he should live a life of proper trolldom, the Queen mistakenly and unknowingly sending him to Central Park in New York, where he feels right at home with the lush plant life all around. It is there that he creates a few friends of his, each of them flowers, though he longs for some genuine and organic friendship. One day, a young brother and sister are out in the park, their relationship broken, with the Brother, Gus, a brat who is often distant and focusing on technology and having grown up too fast, while Rosie, the sister, wants a simple connection with her brother. By luck, they happen upon the friendly Troll's home under the bridge, befriends the two. But, when the wicked Queen and her cautious King Llort see that Stanley is not where she intended to place him, she tries everything in her power to do away with him, before eventually deciding to deal with him herself, tearing Central Park to pieces and endangering all within it. Only Stanley and his friends can stop the madness.
