U is a fictional thriller centred on Rachel, a brilliant organic chemist trapped in a mundane life working for a pharmaceutical company developing libido-enhancing drugs. Her husband Sam, is much less talented and is dissatisfied with life. He accumulates crippling debts due to a gambling addiction. Their desperate situation catches the attention of Massey Mancuso, a wealthy, enigmatic businessman with a social conscience and an ambition to develop the ultimate recreational drug to combat the harm caused by existing substances. Massey makes a Faustian offer to Rachel and Sam: he'll help them pay off their debts if Rachel can develop the ultimate recreational drug. Rachel, initially repulsed, becomes emotionally invested in the project and is drawn to Massey. When Massey intervenes in a domestic violence incident involving Rachel's sister Lizzie, it sets off a chain of events leading to danger and revenge.Rachel's relationship with Massey strains her marriage, but she achieves development of a drug that surpasses expectations. Massey persuades her to test the drug in his nightclub. On the night of testing, a rival crime lord's son is poisoned, possibly by the new drug. Chaos ensues and Rachel has a falling out with Massey, leaving her on the run and needing to prove her innocence. A twist is revealed regarding the effect of the drug and the identity of the poisoner, with fatal consequences. The story ends with a morally ambiguous synergy between the criminal underworld and big pharma in the realm of pharmaceutical innovation, all against a backdrop of a high-stakes quest for the ultimate recreational drug.