Amabel Grey, a widow with a modest income, needs money. Fast. Her spoiled daughter Daphne has an opportunity to go with friends on holiday, and she's convinced it will end with a lucrative marriage proposal. But where to find 200 pounds? She overhears a client requesting the lawyer find someone to live in his Dower House for six months. The stipend is 200 pounds! And she knows the house, having visited 20 years before. The catch? Previous tenants have been driven away by strange happenings, and the village is convinced the place is haunted. The owner wants the rumors to stop.

As a mute, burly German peasant is helping British soldiers move a fallen tree, he's struck on the head. When he regains consciousness he calls out to the astonished Major Manning, using his nickname "Monkey"—in perfect English.

Twelve-year-old Peter Waring is an orphan with an assortment of relatives who don't quite know what to do with him. But Peter's concern is for Rose Ellen, the little girl his mother took in before she died, and for whom none of his relations feel any responsibility. They are however intrigued by Peter's legacy. His father had hidden The Annam Jewel, a mysterious and priceless object that Peter will inherit on his 25th birthday. But Peter's first task is to rescue Rose Ellen from the wretched institution where she has been sent.

The engagement of effervescent Mally Lee to handsome, well-connected Roger Mooring is not going well. They quarrel constantly and Mally's idea is to spend time apart and delay the wedding. She has no money of her own and hopes to find a job, which materializes when Sir George Peterson hires her to be a governess to his daughter. She happily heads to London and all is well until Sir George and his odious secretary, Paul Craddock, accuse her of the theft of a diamond brooch and an important paper.

Timid Renata Molloy is in mortal peril after overhearing details of a breathtaking conspiracy. But her courageous and near-identical cousin Jane Smith—homeless and just two-and-elevenpence away from the workhouse—is willing to take her place if it means a roof over her head and plenty to eat. So Jane, with the help of Captain Henry March of Scotland Yard, whose hand in marriage she once refused, finds herself incognito at stately Luttrell Marches, enmeshed in a mystery of secret formulae, political plots, and a maze of secret doors and secret passages …