In Staub's latest suspense novel (following last year's bestseller The Final Victim
), four Massachusetts sorority sisters make a pact following the accidental death of their sorority sister, Rachel Lorant, on her birthday; together, they swear never to speak about what they saw that night. Ten years later, the women start receiving mysterious letters alluding to Rachel's demise. When one of the four is brutally murdered on the night of her birthday, the others begin to worry what their own encroaching birthdays hold for them. While police try to track down the murderer, our heroines hold tight to their secrets, even as they're hunted and killed one by one. By the time the past finally does come to light, it may be too late for one desperate survivor. Though her prose is strictly utilitarian, Staub keep things taut and unpredictable, changing perspective often and offering up a whole school of red herrings; capped with a gratifying conclusion, Staub's latest is a surprisingly effective thriller. (May)