The Darkest Secret by Alex Marwood

When Mila Jackson's father, Sean, dies of a heart attack, she is forced to revisit all the trauma and dysfunction her family has to offer. Sean was a wealthy property developer who married four times and was an absent father to his daughters. Twelve years ago, during Sean's 50th birthday weekend, three-year-old Coco Jackson disappeared. Coco was Mila's half-sister and Sean's daughter and the media had a field day when she vanished. Now, with Sean's death, the mystery is brought up again. Mila finds herself in the middle when she agrees to bring Coco's twin, Ruby, to the services. Alternating with the contemporary story is the tale of Coco's vanishing, told from the point of view of Sean and his deplorable friends. The big question is--what really happened to Coco? Marwood spins a story of secrets and loss with a zinger of an ending.