Ray Ferrier is a divorced dockworker and less-than-perfect father. Soon after his ex-wife and her new husband drop off his teenage son and young daughter for a rare weekend visit, a strange and powerful lightning storm touches down.
After losing their mothers at a young age, Diamond and her closest cousins, Tia and Tara, known as "Sisters", are willing to do anything to keep their grandmother from dying of cancer and save their family.