Silent Voices by Patricia Gibney

When Rachel Mullen is found dead by her only sister Beth, her body twisted in an arc of pain, Detective Lottie Parker knows that she has been murdered the minute she enters the bedroom. Lottie’s heart aches for Beth, all alone in the world, whose last memory of her sister will forever be the brutal way she was taken. And when Lottie finds a shard of glass placed in the young girl’s throat, she fears that Rachel may be just the first victim. The night before, Rachel had attended a party at a luxurious new restaurant in Ragmullin, and Lottie wastes no time in tracking down the other guests. But there are several things troubling her: Rachel’s handbag and keys are nowhere to be found, and no one at the party seems to have seen her leave. Just as Lottie thinks she’s onto something, her worst fears are confirmed: another woman is found murdered, with glass in her throat.