The Vanishing (Triquetra #2)
L.C. Kincaide

She must have been important because the mysterious client spared no expense to get her there to investigate the disappearance, making the gig too good to resist.
Had Lindy known the victim’s identity, and her own financial reality were not so grim, she would have turned him down in an instant. Instead, she travels to a remote island with a man she’d rather avoid, and where the residents keep their secrets close.
One of them knows the truth, and she must find it before it finds her.