Time is not a river. It is a vast cosmic sea, where each life exists as rippling circles on its surface. Usually, the eternal ocean oscillates in harmony, all lives breathing up and down as one. But something has broken this equilibrium, turning the cosmic ocean into turbulent waters.

In 1828, Daniel Ashton, Lord Whitmoor, faces a problem of epic proportion—an earthquake has caused the time portal in Duir Cottage to stop functioning, disrupting the cosmic ocean and threatening Time itself. He needs a computer to crunch numbers and provide a solution. But with the time portal on the fritz, a computer is two hundred years in the future. So Daniel sets out to find the next best thing—an anonymous mathematical genius of legendary renown.

Fossi Lovejoy knows she is too odd, too intelligent, too old, and too poor to ever marry. So she busies herself in her father's ministry and her mathematical equations, choosing to focus on what she has, not what she lacks. But then Lord Whitmoor publishes one of her private theorems, taunting her to respond. Fossi is compelled to action—when you have so little in life, you defend the few things that are yours with ferocious tenacity. Even if it means matching wits with the infamous Lord Whitmoor. Can two people past their youth find unexpected love?