A really great book is "Mrs. Bartheleme's Madness" by Susan Claudia. It is set in the 1970's and is about a housewife (Mrs. Bartheleme) who is driving along one Halloween night and suddenly in front of her car is a group of teens in costume, she slams on the brakes and one girl screams "you've killed my brother!" Then the pack of teens start running toward her to attack her (she thinks). She flees home to call the cops (pre-cell phone days) and when the cops come there are no teens, no dead or injured boy, nothing. Her family thinks she made it all up. Lots of twists and turns in this book and the reader is blindsided by the ending. Big shock. Try to find it and read it!