A scientist should never cohabitate with his annoyingly hot nemesis—it's a recipe for combustion. Mara, Sadie, and Hannah are friends first, and scientists always. Although their fields of work may take them to different corners of the world, they can all agree on a 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 leave the thermostat alone. And don't steal other people's food. And other rules that Liam, her nasty neighbor, an oil lawyer, knows nothing about. Okay, okay, technically she's the interloper. Liam had already settled into his aunt's house like some sinister grumpy giant when Mara moved in with him, with his big muscles and kissable mouth, just sitting on the couch and enticing respected scientists to turn to the dark side... but Helena was her mentor, and Mara isn't going to move out and give up her inheritance without a fight. The problem is that living with someone means getting to know them better. And the more Mara learns about Liam, the harder it is to hate him... and the easier it is to love him.