Mara, Sadie, and Hannah are friends first, scientists always. Though their fields of study might take them to different corners of the world, they can all agree on this universal truth: when it comes to love and science, opposites attract and rivals make you burn…. As an environmental engineer, Mara knows all about the delicate nature of ecosystems. They require balance. And leaving the thermostat alone. And not stealing someone else’s food. And other rules Liam, her detestable big-oil lawyer of a roommate, knows nothing about. Okay, sure, technically she’s the interloper. Liam was already entrenched in his aunt’s house like some glowering grumpy giant when Mara moved in, with his big muscles and kissable mouth just sitting there on the couch tempting respectable scientists to the dark side…but Helena was her mentor and Mara’s not about to move out and give up her inheritance without a fight. The problem is, living with someone means getting to know them. And the more Mara finds out about Liam, the harder it is to loathe him…and the easier it is to love him.