Prehistoric creatures have again invaded Crater Lake National Park - and this time there's more than one.

Henry Shore has been Chief Park Ranger at Crater Lake National Park for thirteen years now and thought the days when he'd had to fight a rogue dinosaur that lived in the caves below the lake were long over.

Until one of his park rangers, to save a visitor's life, is in a deadly struggle out in the woods with a new breed of dinosaur worse than the last one. It's as big as a man, but this one is a young one. And growing.

Then more of the creatures begin to show up everywhere, threatening people and destroying the tranquility and safety of his beloved park. A tourist trolley filled with fifteen people is snatched up off the crater's rim by another version of the younger one…but this one has grown into a giant with fangs, claws and a deadly tail. And this one has wings.

Ugly Gargoyles, Henry calls them. For this one isn't alone.

They're flying beyond the park's boundaries into the neighboring towns.

So Henry, with the help of his son-in-law, a paleontologist named Justin, and a band of brave park rangers, and a few good soldiers, must not only protect his park and his people from monsters once more but find their lair and destroy it and them before the creatures kill again.