They have opened The Gate. Pray it's not too late.

The Gate (1987) Three young children accidentally release a horde of nasty, pint-sized demons from a hole in a suburban backyard. What follows is a classic battle between good and evil as the three kids struggle to overcome a nightmarish hell that is literally taking over the Earth. The Gate II: The Trespassers (1990) It's been five years since Terry's friend Glen discovered The Gate to hell in his backyard. Glen has now moved away and Terry begins practicing rituals in Glen's old house and eventually bringing back demons through The Gate and leading to demoniac possession and near world domination.