The delightfully funny first book in Marjorie Weinman Sharmat's beloved Nate the Great series opens with the eponymous' character's straight forward personality introducing himself: "My name is Nate the Great. I am a detective. I work alone. Let me tell you about my last case." He tells readers he has just eaten a good breakfast of "pancakes, juice, pancakes, milk, and pancakes," then he deadpans "I like pancakes." He receives a phone call from his friend Annie who lives down the street. Annie tells him she has lost a picture and asks if he can help her find it. His reply: "I have found lost balloons, books, slippers, chickens. Even a lost goldfish. Now I, Nate the Great, will find a lost picture." Nate says he'll be over in five minutes and tells Annie not to touch anything and "DON'T MOVE." Annie tells him her foot itches, and Nate contradicts himself saying "Scratch it."
Nate leaves a note to his mother, stating that he always leaves a note to his mother when he's on a case. When he arrives at Annie's house he notes that she is eating pancakes, a good breakfast. He asks her about the lost picture. Annie tells him that she painted a picture of her dog Fang and put it on her desk to dry, but it disappeared yesterday. Nate remarks that she should have called him yesterday when the trail was hot. He asks Annie if her house had any trapdoors or secret passages. She says no and he says the case is going to be dull. "I have a door that squeaks," Annie replies. "Have it fixed," Nate commands. Nate asks Annie to show him her room. Nate looks everywhere in Annie's room and is sure of one thing, that "Annie liked yellow." But he doesn't find the missing picture of Fang. Nate asks Annie who has seen her picture, and she says her friend Rosamond, her brother Harry and her dog Fang. When she says her dog Fang doesn't count Nate says "Everybody and everything counts."
They track down Fang in the backyard and Nate suggests that Fang may have buried the picture in the holes he dug. Nate and Annie dig in the backyard for two hours but only find rocks, bones, worms, and ants. Nate declares that he is hungry and Annie offers him pancakes. Nate thinks "I could tell that Annie was a smart girl. I hate to eat on the job. But I must keep up my strength." After he eats pancakes they visit her friend Rosamond's house. When Nate introduces himself to Rosamond as a detective she asks him to help her find her missing cat Super Hex. Nate and Annie go in her house and Nate observes the pictures all around. He sits down in a chair and accidently steps on a cat's tail. Rosamond screams "Super Hex!" She remarks "You found him! You are a detective." Nate smugly replies "Of course." They leave Rosamond's house and Nate concludes that Rosamond did not have the picture because she only likes cats. Nate asks Annie "Now where is your brother Harry?"
Nate meets Annie's little brother Harry who has red paint all over him. Harry says "Me paint you." Nate misinterprets this and says "Good. No one has ever painted a picture of me, Nate the Great." Harry paints Nate red and Annie laughs at him. Nate did not laugh and went back to solving the case. He looked around the room and could not see it. He wondered who could have the picture since everyone who saw it did not appear to have it. Nate looked at the wall in Harry's room again and solved the case. He told Annie to look at the pictures that Harry painted. He pointed out the orange monster at the end with three heads. "So what?" Annie asks. He tells her that Harry paints with red. He concluded that Harry took Annie's yellow picture of Fang while it was still wet and painted it over with red to make orange. He compared the shape of the monster and the shape of the dog that Annie drew of Fang. "The case is solved," Nate announces. Annie says she doesn't know how to thank him. He asks her is she has anymore pancakes. "I hate to eat on the job. But the job was over," Nate rationalizes. Annie tells Nate that she will paint another picture. "Will you come back to see it?" Annie asks Nate. He says he will if Harry doesn't see it first. Annie and Harry smile at each other and Nate smiles. "I, Nate the Great like happy endings," Nate declares as he walks home in the rain with his rubber boots.