The Grémillet Sisters: The Mountain Goat and the Comet (The Grémillet Sisters #4)

The Grémillet sisters are heading to the mountains for a long-awaited reunion with their dad. But as always, things don't go as planned... With their astronomer father preoccupied with a soon-to-arrive comet, Sarah, Cassiopeia, and Lucille set out on their own to explore the region and it isn't long before they stumble onto a new (four-legged) mystery!