Dark Rising.

A weekend camping trip turns into a frantic fight against the supernatural when an ancient demon and a fearsome female warrior bring their eternal battle into the present day. Jason Parks is trying to win back his ex-fiancee, Jasmine, by arranging a camping trip with the lost love in question, his best friend, Ricky, and their witchcraft-obsessed friend, Renee. Little does Jack realize that Jasmine has switched teams--these days she's more interested in seducing Renee than marrying the man she once loved. But lately Renee's been having horrible dreams about Summer Vale, a little girl who vanished without a trace 20 years ago. When Renee attempts to contact Summer's spirit, she inadvertently opens an interdimensional portal and unleashes a vicious demon. Fortunately for the frightened campers, a grown-up, sword-wielding Summer manages to get through the portal as well, and sets out to slay the malevolent hell-spawn.