Lies My Mother Told Me

Spanning 10 years, Laren Sims is a single mother living in Destin, North Carolina with her parents and young daughter Haylei. Outgoing and free-spirited with a reputation of being a trouble-maker and having sociopath tendences to shamelessly lie, cheat, and steal without any guilt to her actions, Laren cannot shake off her bad reputation or break free of her quick and easy life of crime. Unable to afford Christmas presents, she pays with a stolen credit card. She is caught, and is sentenced to 90 days in a maximum security prison.Some months later, Laren continues to get off on the "rush" of stealing. During a shopping outing at a local mall, Laren steals items from a clothing store when she takes her daughter with her to show her the art of stealing. Rather than return to prison when she is found stealing a second time, she goes on the lam, but decides to take her daughter with her unable to stand being apart from her. Laren steals a car with her daughter, and travels to another town in Tennessee. There, she steals another car from a used car lot when she leaves a stolen credit card as security with the dealer while allegedly taking it for a test drive. Mother and daughter work their way across the country, supporting themselves by passing bad checks and using stolen credit cards while frequently stealing license plates from other cars in order to escape detection.Laren adopts the identity of a diner waitress she meets in rural Texas by stealing her driver's license out of her locker. She and Haylei ultimately arrive in Las Vegas, where Laren applies for a job with Lucas McKenzie, a wealthy alcoholic attorney and ranch owner under the name of Allison. The two fall into a toxic co-dependent relationship and eventually marry. Laren embezzles $90,000 from her husband's business account and he subsequently is disbarred for reasons not made clear.In an uncharacteristic moment of honesty, Laren reveals to Lucas that she is actually from Destin, North Carolina and has had problems in her past. Lucas uses this information to find out Laren's actual name and her sordid past. From this point on Lucas threatens to turn her in to the authorities if she refuses to co-operate with him in helping more of his shady business ventures. In a state of fear, Laren sends Haylei away to school and hires a college student, named Kristin, to help her with the horses on Lucas' ranch. The two become very close (although never specified, a lesbian relationship between them is implied), to the dismay of both Lucas and Haylei. As their relationship disintegrates and the possibility of discovery grows, Laren decides to poison her spouse with Kristin's assistance.One evening, Laren approaches Lucas in his hotel room during a conference where she poisons him. Laren and Kristen then remove the body from the hotel where they bury it under a bridge spanning a shallow creek, and it eventually is found.Laren escapes with Haylei and leaves behind Kristin to shoulder the blame. Returning to Destin, she encourages her daughter to contact her grandparents and return to them, then surrenders to the police and eventually commits suicide, by hanging herself in her jail cell.

Question: How does Laren and Lucas' relationship end?
Answer: She poisons him