In this so-so domestic thriller from McDonald (Behind Every Lie), happily married physician Emma Sweeney and her police detective husband, Nate, dote on their precocious five-year-old son, Josh. Then Josh is diagnosed with a rare form of leukemia, and their insurance won't cover his costly treatment. After they're turned down for loans, Emma believes the only way to raise the cash is to sell opioids to addicts and forged prescription orders to drug dealers. Meanwhile, Nate, who knows nothing of Emma's scheme, volunteers to work with the DEA to find the source of opioids invading their town of Skamania, Wash., in the hope of a promotion. The weak plot spins on Emma's rationalization that in trying to save Josh she's also helping those who truly are in pain, but whose medication has been cut back because of government crackdowns. Emma's plan soon goes awry as the bodies pile up while her inexperience puts herself and her loved ones in danger. This well-meaning effort to highlight the opioid crisis spins out of control with clichés, shallow characters, and a preachy narrative. McDonald has done better. Agent: Carly Watters, P.S. Literary (Canada). (Feb.)