PHANTOM OF THE 13th FLOOR by Marilyn Ross (Popular Library 1975)

It's Christmas in New York. In a Broadway revival, Joan Crane is playing the role her grandmother made famous. Her grandmother--who plunged to her death from the rooftop of the nearby Brant Hotel. Though Joan has avoided the Brant, she accepts an invitation to a party there, where a spectral elevator operator takes her to the 13th floor, which does not exist, and a mysterious hypnotist who's been dead for many years sets her nightmare in motion. After that, she begins to have blackouts. She always snaps out of them in strange places, only to find that someone she knows has just been murdered! The blackouts get worse and the bodies pile up. She fears she's being possessed by the ghost of her vengeful grandmother, to whom she bears an uncanny resemblance. To exorcise the world of phantoms that seems to have swallowed her, she arranges a dreadful gambit: re-enact the party where her grandmother either committed suicide or was murdered.

Although described on the cover as a "gothic," the setting is contemporary and urban, and it unfolds very much like a murder mystery. Even on the assumption that ghosts may be involved, the characters attempt in classic amateur-sleuthy style to solve the original puzzle of the grandmother's death as the key to solving the series of murders taking place around them. This has a nice giallo-esque feel to it, right down to some outrageous red herrings and improbabilities you just have to grin and shake your head at, and despite the fact that all killing happens "offscreen." I recommend it, and given the Christmas setting, now is the perfect time to see about getting yourself a copy and enjoying it this holiday season.

By the way, Marilyn Ross is probably best known for the Dark Shadows novels, and happens to be a pen name for Dan Ross. Read an interiew with him here, and with his wife--the real Marilyn, from whom he "borrowed" the pseudonym--here.