During a rain storm, Lyla convinces Sirena to use her Moon Ring to change the weather until it backfires and it snows indoors. Exposed to the frost, Lyla and Sirena develop an increasing "snow rash". Nixie and Rita must find a cure for the rash before the girls are taken to the hospital. Meanwhile, this rainy day is also the day Zac and his father go out camping. Desperate to hide his merman secret, with advice from Cam, Zac uses his powers to force a fever to stall his father.