When Annie tells him about her missing painting, Nate the Great and his trusted companion, Sam Spade, set out to investigate, gather clues, and solve the mystery.
While traveling on the train to San Francisco with his cousin Olivia's owl, Nate the Great and his dog Sludge must use all of their detective skills when the owl suddenly disappears.
Even a deep snow the week before Christmas can't keep Nate the Great and his dog Sludge from finding the special card sent to Annie's dog Fang by his mother.
When Rosamond's birthday gift for Nate disappears from her sled, the boy detective decides to unravel the mystery. In braille with interlinear typescript.
As Nate the Great sets to work on his first international case, he searches for a lost "something" and saves the King of Sweden from a troublesome traveler.
In spite of a phony clue and trouble from a fierce cat, Nate the Great is able to use his skills of detection to find the remaining parts of an incomplete message left mysteriously on his doorstep.