At the turn of the 20th century, Vivian Lesperance is determined to flee her origins in Utica, New York, and avoid repeating her parents’ dull, limited life. When she meets Oscar Schmidt, a middle manager at a soap company, Vivian finds a partner she can guide to build the life she wants-not least because, more interested in men himself, Oscar will leave Vivian to tend to her own romances with women. But Vivian’s plans require capital, so the two pair up with Squire Clancey, scion of an old American fortune. Together they found Clancey & Schmidt, a preeminent manufacturer of soap, perfume, and candles. When Oscar and Squire fall in love, the trio form a new kind of partnership. Vivian reaches the pinnacle of her power building Clancey & Schmidt into an empire of personal care products while operating behind the image of both men. But exposure threatens, and all three partners are made aware of how much they have to lose. For readers of Hernan Diaz’s Trust and Colm Toibin’s The Magician, with echoes of Gustave Flaubert and E.M. Forster, Mutual Interest is a beguiling story of queer romance, empire, and power.