Sally Meredith's young life has been full of adventure. As a suffragist, she fought for women's right to vote. She drove an ambulance in France during the war. And she's already had a proposal and a broken engagement. But the past few years have been deadly dull, taking care of a cranky relative and now living alone in a quiet village. So when her eccentric uncle Fritzi arrives with the tale of his most recent invention - a deadly gas that nations are striving to get hold of - she's intrigued.

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.

It is a black Chinese cabinet decorated with figures that once ignited little Chloe Dane's imagination. It was in the drawing-room of her family home, Danesborough. Later, it held secrets that shamed and sickened her. Poor but honest Chloe hasn't been to Danesborough for years and believed she was the last of her family. So when a distant cousin introduces himself and declares that she will be his heir, she finds herself in the huge house again. And she wants none of it.

Sir John Waveney has inherited Waveney Hall. A veteran of the Great War himself, his inheritance has come because of the deaths in action of his two distant cousins, leaving him as the next male heir. He hopes to make the acquaintance of his two remaining cousins, Lady Jenifer Marr and Anne Belinda. But Lady Marr proves very vague about her twin sister's whereabouts. Is she traveling with a friend or (as has been intimated) has she been incarcerated in a mental institution? No one seems to actually know, and several people seem bent on frustrating John's attempts to find her.