Uncertain Murder (Watchbearers, Book 3) - James Litherland

IN THE SUMMER of 1992, tech billionaire Brandt Keener dies drinking a glass of wine while dining with his nearest if not dearest on his small private island off the Washington coast.  Despite suspicious circumstances and an abundance of motives, the police find no evidence of homicide, and three weeks later the same people who were present at his death gather again for the reading of his will.
    Convinced the man was murdered, time-travelers Sam and Bailey inveigle themselves onto the island to investigate, but soon their best suspects start to die.  Does Keener’s killer have some reason to want them dead as well?  Or could the murdered man’s ghost be seeking revenge?  With Bailey’s help, Sam is determined to find the truth—even if it puts both their lives in jeopardy.