Always on the prowl for good new clients, John Mariner helps a wealthy and successful private wealth manager, Greg Robertson, buy a large ranch north of Blanco, Texas. Their relationship warms over several months, but shortly after meeting him, Robertson's private plane crashes on the way to Houston from his ranch . As executor of Robertson's estate, Mariner needs to figure out the circumstances of Robertson's death. As he sorts that out and arranges for a probate of the estate, Mariner finds the estate embroiled in controversies surrounding Robertson's investment firm, centering on allegations that the firm was operating a sophisticated Ponzi scheme. The FBI launches an investigation into the circumstances of Robertson's death, and they and Mariner find themselves entangled not only in a financial mess, but an illegal diamond operation and domestic squabbles between Robertson and his wife. Murder or suicide?