Penrose, Andrea. Wrexford & Sloane historical mystery #9

"A welcome interlude of calm has descended on Wrexford and Charlotte, though with three lively young boys in their care and an unconventional circle of friends and allies, quiet rarely lasts long. And sure enough, in the dead of night, an old acquaintance appears and asks for help. His brother-in-law has been accused of murdering a fellow member of the prestigious Royal Society at their London headquarters in Somerset House. Wrexford agrees to investigate, and with a little unexpected help from their young charges, discovers that what seemed a simple crime of passion may be part of a far darker and dangerous plot, where science, money, and politics collide. A mysterious new technical innovation threatens to ignite a crisis throughout Europe, with frightening consequences for London's financial world. There is also personal upheaval for Wrexford and Charlotte, when a shocking secret from the past brings a profound change to their family, testing the bonds of loyalty and trust as never before ..."--Dust jacket flap