Here's a bit about it from Goodreads:
In 1893 a storm sweeps through London, while Arthur Shaw—a young astronomer with a side career writing fiction—is at work in British Museum Reading Room. The storm wreaks unprecedented damage throughout London. Its aftermath of the storm Arthur’s prime literary market closes, owing him money, and all his debts come due at once. His fiance Jo takes a job as a stenographer for some of the fashionable spiritualist and occult societies of fin de siècle London society. Meanwhile, Arthur deciphers an encoded newspaper ad seeking able young men. It seems to be a clerking job doing accounting work, but the mysterious head man Mr. Gacewell offers Arthur a starting position at a salary many times what any clerk could expect. The work is long and peculiar, and the men spend all day performing unnerving calculations that make them hallucinate or even go mad...but the salary is compelling.
Things are beginning to look up when the wages of dabbling in the esoteric suddenly come due: a war breaks out between competing magical societies, and Arthur interrupts Jo in the middle of an elaborate occult exploration. This rash move turns out to be dire, as Jo’s consciousness is stranded at the outer limits of the occultists’ psychic day trip. Which, Arthur is chagrinned…
And I so adore that cover! The Revolutions is due out from Tor on April 1.