The Warning is a religious tract written by Jack Chick. It was originally printed in 2000, and remains an in-stock title. It is listed on their website under the subject "Basic Gospel" and also tagged as "Older Children and Adults".
The tract begins with an accident where the driver failed to stop at a stop sign. Later at home, Bobby (a teenager) and his grandfather discuss the accident. His grandfather then tells of how his father (later in the tract, the great-grandfather's name is given as Tommy) almost died not obeying a warning sign, only to be miraculously stopped by a piece of barbed wire (which the grandfather has maintained over the years).
Grandfather then tells the story: Tommy's older brother Henry is approached by two friends who found a new swimming hole by "the old Simpson place". Henry asks if Tommy can come along as he had learned to swim that summer and is allowed to come. As the boys ignore prominent warning signs, Tommy has his overalls caught on the barbed wire. He is able to finally free himself, but before he jumps in Henry tells him to stay away as the pond is filled with snakes; the snakes kill Henry and his two friends.
Two weeks later, using the tragedy as a backdrop, a preacher tells the story of Adam and Eve; Tommy accepts Christ, later becoming a Bible-believing preacher. Recognizing his own need for salvation, Bobby prays to receive Christ.