Excited at the prospect of meeting Timothy's Native American pen pal at an All-Tribes Powwow, the three cousins soon find themselves involved in another investigation when they discover a thief in their midst.
Titus and his cousins are taking care of their neighbors' crabby Yorkshire terrier when the dog suddenly becomes sweet-tempered and the cousins have a mystery on their hands.
Ten-year-old Timothy and his cousins Sarah-Jane and Titus, who make up the Three Cousins Detective Club, investigate when all the lawn ornaments in the neighborhood disappear and then are put back in the wrong places.
When the three cousins find some strange symbols carved in an old tree, they start learning about hobo code and in the process learn about the importance of kindness as well.
After Timothy copies a papier-m?ch? snake from a mural for a Christmas present for Titus, he and his cousins find that the snake on the mural has changed.
