The conclusion to the  Frightening Four miniseries! On a  hill on the outskirts of Sweet Valley sits a  beautiful old Victorian house. It stood empty until a  few weeks ago, when a big family moved in . . .  the perfect clients for Elizabeth and Jessica  Wakefield's new baby-sitting service . . . .   Identical twins Elizabeth and  Jessica Wakefield and their friends have learned one  thing from baby-sitting for the Riccoli family:  dreams can come true . . . and so can nightmares. When  the fire in Andrew Riccoli's dream turned to real  flames, the twins took action. They killed the  evil creature--half girl, half monster--in the kids'  nightmares. Before she killed  them. Now that the  beast is dead, the Riccoli kids will have sweet  dreams again. Or so they think. But the creatures  has left the kids' nightmares to terrorize them in  real life. And waking nightmares  are the scariest of all.