Fog Island Flowers by Tonya R. Moore

Jonathan Baron's music has left him and so has the love of his life, a woman he's no longer certain even really exists. Convinced that his buried childhood memories are the key to determining whether or not she was merely a figment of his imagination, he seeks out his family's ancestral home.

From the moment he sets foot unto Fogg Island, things just don't seem quite right. Anna, Eloise and Sorcha claim to be his last living relatives but it's glaringly obvious that none of them are actually related to him by blood. By the time he crosses paths with the ghostly and subtly terrifying Cassandra, Jonathan will already be entangled in an eons old saga of murder, madness, and macabre alien science...