At the Hanover country estate, as Mister Marmee and Sir Happy Heart take a much needed respite from the rigors of London life, they discover the wicked never go on holiday. As the bodies pile up in what the local authorities are calling "unfortunate accidents," the detective duo begins to suspect there is much more to these mishaps than meets the eye. When evidence of faerie mischief begins to intertwine among the deceased, Sir Happy strikes out on his own to dig up the truth. When Sir Happy is unjustly accused of attacking a well respected man and finds himself a fugitive, it is up to Mister Marmee and a menagerie of animal friends to come to his rescue and clear his name. The only direction Mister Marmee receives from Sir Happy before he disappears is to "follow the faeries." Could the answers to Mister Marmee's questions lie in the shadowy Banum's Wood with an Irish healer named Biddy Early, or is the mystery behind Sir Happy's plight and the murders he was investigating beyond even her all-seeing eye? Mister Marmee will have to use all of his wits to save his friend and solve the mystery of the wayward fae before Sir Happy becomes the next victim.