What do you want so badly that you can taste it&;and can you persuade someone to give it to you? That&;s the subject of a writing assignment Calvin&;s fourth-grade teacher, Mr. Purdy, gives the class. Calvin wants a dog! He reads what he&;s written to his mom to see just how persuasive he can be. No way, Mom says: Stella, their babysitter, might be allergic, and Calvin is too irresponsible to care for a pet.Luckily, Mom&;s boyfriend, Ledward, is on Calvin&;s side. He takes Calvin to a place he calls dog heaven. There Calvin meets the dog of his dreams&;Streak. Now Calvin&;s got to convince Mom he&;s dog-responsible, because he and Streak belong together!