The case of the counterfeit painting

While searching for her friends at the Dino Festival, Clementine Wim runs into two people carrying what she thinks is the Tiled Lunch Counter (a famous painting) away from the Capitol City Art Museum, but when she checks the painting is still hanging in place--and before she can track down the thieves, and prove that the painting now in the museum is a forgery, she has to convince her friends that she was not imagining things.