R. T. Raichev 
Hunt for Sonya Dufrette [EPUB ebook] 

On the day of the Royal Wedding in July 1981 at a house party by the Thames, a little girl vanishes. Her doll is found floating in the river, but of the child herself there is no sign. Twenty years on and Antonia Darcy, divorcee and assistant librarian at the Military and Naval Club, still puzzles over the disappearance of Sonya Dufrette and the bizarre behaviour of her father, the awful Lawrence Dufrette, his exotic wife, Lena and the intelligent but austere Lady Mortlock — not to mention the strange absence of the nanny. Ably assisted by her new admirer, Major Payne, she embarks on a mission to solve the labyrinthine mystery of the long-lost child’s disappearance.