Where is Pluto?

The Sun has a problem—she can’t find Pluto anywhere! He usually stays far at the back of the solar system, but now he’s completely disappeared. Mercury is too hot, Venus can’t see through her thick clouds, and Earth is busy watching her humans. As the planets search from the rocky inner worlds to the icy outer reaches, they discover something is very wrong with their distant friend. What could be making Pluto so upset?