Murder on the Potomac — Margaret Truman

Law professor Mac Smith has unflagging passion for two things in his life: his wife Annabel and the majestic Potomac River. When Mac discovers a weed-shrouded body in the latter, the former gets edgy. Lovely Annabel, owner of a flourishing Georgetown art gallery, must not only endure her husband's obsession with another killing, but she must believe Mac when he says that a stunning female former student is one of the only people who can help him.

They discover that the corpse was once the "confidante" of a wealthy Washingtonian, which leads to the Scarlet Sin Society, a theatrical group that--perilously--reenacts historical murders. And soon, the only thing that matters more to Mac than solving this serpentine case is preventing Annabel's untimely death....