Mary Rose and Jo-Beth, the sisters first met in Help! I'm a Prisoner in the Library, have a more entertaining and spooky adventure here, en route to California with their reporter-father who is given to turning off onto byways and ""chasing after will-o'-the-wisps,"" as his wife has put it. (She's flying out with the baby.) Tired and hungry and far from civilization, the three follow a faded old sign to the ""Inn of the Whispering Ghost"" on Skull Valley Road. . . and find themselves in a typical ghost town--the scene, according to an old newspaper they find there, of a gold Find, a murder for the gold, a subsequent hanging, and a threatened haunt. Now someone, maybe the ghost, has put a record on the old victrola, and someone has just cooked up bread and beans in the inn's old kitchen. Upstairs, Mary Rose opens a ""bedroom"" door that leads nowhere. (Fortunately, she falls onto a hay wagon below.) After a scary night there, Daddy figures out that the town is really an old movie set, with most of the storefronts just that--but it's Mary Rose, with her sister's help, who saves them all from a not-so-villainous villain, a senile former actor who has locked ""Black Bart"" Daddy in the jail and got the girls lost in a mine. The story ends cozily, and throughout the adventure there's a sense of normal-family security that keeps the event from being scary but doesn't spoil the mildly shivery fun.