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....Under One Roof. An environmental engineer discovers that scientists should never cohabitate when she finds herself stuck with the roommate from hell - a detestable big-oil lawyer who won't leave the thermostat alone. Stuck with You. A civil engineer and her nemesis take their rivalry - and love - to the next level when they get stuck in a New York elevator. Below Zero. A NASA aerospace engineer's frozen heart melts as she lies injured and stranded at a remote Arctic research station and the only person willing to undertake the dangerous rescue mission is her longtime rival.