In the final pages of The Third Rainbow Girl — a new book about the aftermath of the murders of two young women who were hitchhiking in West Virginia in 1980 — author Emma Copley Eisenberg interviews a friend of the victims. Elizabeth Johndrow parted company with her friends a day before they were murdered; she’s the “third rainbow girl” of the title. Eisenberg asks Johndrow, now in her 50s, why she and so many other young women hitchhiked back then. Johndrow says: Well, there was adventure to it … [H]itchhiking was like falling forward into the universe that you wanted … The Third Rainbow Girl is a haunting and hard-to-characterize book about restless women and the things that await them on the road. At its simplest, it’s a true crime story about the still-unresolved murders of Vicki Durian, 26, and Nancy Santomero, 19. Durian and Santomero had been hitchhiking from Arizona to the Rainbow Gathering — an counterculture peace festival held in the Monongahela National Forest in West