Eddie was excited about the Gems and Minerals exhibit, because he loves jewels and treasure. He remembered from a magazine that his birthstone was topaz, so he kept a look out for that, and eventually we came across a really enormous topaz.
On Monday, he drew a comic about a villain who decides to steal the topaz from the museum.
Luckily, the police put Dog Man on the case. Unfortunately, the topaz is not actually recovered before we reach "The End" (Eddie tells me that the story will be continued.)