One day, Horton the elephant hears a cry from help coming from a speck of dust. Even though he can't see anyone on the speck, he decides to help it. As it turns out, the speck of dust is home to the Whos, who live in their city of Whoville. Horton agrees to help protect the Whos and their home
Joel Barish, heartbroken that his girlfriend underwent a procedure to erase him from her memory, decides to do the same. However, as he watches his memories of her fade away, he realises that he still loves her, and may be too late to correct his mistake.