The year is 1688. Isaac Newton is the most gifted young professor at Cambridge. Yet, when it comes to the opposite sex, he is simply clueless. What does make sense to him, however, is a life dedicated to science. To that end, he and his friend, Edmund Halley, travel to London to present before the Royal Society, England’s elite brotherhood of scientists, in the hope of gaining membership.

Elsewhere, Sophia Charlotte, a Prussian royal who wants nothing more than to be recognized as a scientist, is rejected by the Berlin Academy of Science because of her gender. She decides to disguise herself as a man named Nicolas Fatio in order to apply for membership at the Royal Society. When she attends Newton’s presentation on prisms, Sophia becomes enamored with his unorthodox scientific thinking.

When a comet appears, blazing across the night sky, Newton rushes to observe it. As he sets up, his telescope’s sights accidentally land on Sophia, who is taking measurement of the comet. Newton is smitten. The following day he meets Fatio, who requests Newton’s assistance with his presentation to the Society on comets. In return, Fatio will advise Newton on how to woo Sophia. Newton agrees, not realizing that Fatio is in fact Sophia.

Unbeknownst to Newton, Halley is a spy for the English crown and is tasked with stealing an unproven mathematical system, called fluxions, being developed by Newton. Rumored to be able to predict the future, fluxions may hold the key to preventing a costly war with England’s archenemy, the Dutch Republic. Halley, nevertheless, has doubts about betraying his friend.

Meanwhile, Sophia (as Fatio) demonstrates to Newton how the dynamics of romance is unpredictable, comparing couples to the way statically charged objects react differently to different material. They’re either attracted to or repulsed by one another, and no one can explain precisely why. Newton, however, is more interested in gathering information on Sophia for his equations. Using fluxions to predict the course of a potential relationship with her, Newton finds they are a perfect match. The two soon fall in love. However, Newton has not accounted for one variable: the arrival of Sophia’s ex-lover, Gottfried Leibniz.  

Newton’s Laws of Emotion connects matters of the heart to the laws of motion – inertia, impulse, and equal-and-opposite reactions. It compares the love triangle between Newton, Sophia, and Leibniz to the three-body problem, an unsolvable mathematical scenario that leads inexorably to chaos. Furthermore, the story equates love and gravity, both powerful forces involving attraction. As Newton discovers the laws that shape the universe, he learns there are no rules governing love.