Longing to fight dragons over taking the advice of various family members, spunky ten-year-old Mirka Herschberg hones her skills in her Orthodox Jewish community before accepting a challenge from a witch to defeat a giant troll.

When Mirka is forced to babysit her disapproving little sister Layele, they encounter a wish-granting fish in the woods, but soon discover the fish has a generation-old grudge with Layele's mother--and possesses Layele in order to get revenge.

Mirka is back, and this time she takes on a misguided meteor who's been set in motion by the troll and turned into Mirka's twin by the witch. Doppelganger Mirka is out to best the real girl. Our heroine will have to beat her own other self in a three-park challenge ... or be banished from Hereville!