It's 1910, and Hayley's comet is coming...will it bring Moe good luck or bad? Some people think it will cause fires, floods, earthquakes -- all kinds of terrible things. But Moe knows better. The comet will just be one spectacular show! And who better to watch it with than Grandfather, who has an imagination as big as the sky itself?

But it's not all fun visiting Grandfather's house. The neighbors are unfriendly, and Grandmother is a stern, forbidding woman who'd hiding secrets about the past. And Moe's new friend, Phoebe, swears there's a real ghost in the attic. Then Moe finds out that Grandfather thinks he's going to die when the comet passes by. He's not sick -- but with Grandfather, anything can happen. Can Moe and Phoebe save him?