Vulcan's Kittens (Children of Myth, #1)

12-year-old Linnea Vulkane is looking forward to a long, lazy summer on Grandpa Heph's farm, watching newborn kittens grow up and helping out with chores. That all goes out the window the night Mars, god of war, demands her grandfather abandon her and return to Olympus for the brewing war.

Now Old Vulcan is racing around the world and across higher planes with Sehkmet to gather allies, leaving Linn and an old immortal friend to protect the farm and the very special litter. But even the best wards won't last forever, and when the farm goes up in flames, she is on the run with a daypack, a strange horse, a sword, and an armful of kittens. Linn needs to grow up fast and master her powers, before the war finds the unlikely refugees...