A middle-aged Irish immigrant, Billy has a gift for illusion --- making damaged objects look new. His companion, Charles, the smooth-tongued teenage son of a prostitute, is a natural salesman, just like the mythical father he’s never met. Longtime horse traders and partners, they’ve recently turned their talents to trading mules. But in the summer of 1916, these seasoned grifters skilled in the art of the underhanded deal have just been swindled themselves. They’re saddled with the one thing they may not be able to unload: a gorgeous, murderous black mare named The Midnight Cool.