The Kensington Quartet; Four Charlotte Holmes mysteries set in Europe during the Great War.

LONDON, 1912.
Charlotte Holmes, a brilliant polymath, and her former companion Dr Watan, an Indian doctor, have been estranged for nearly a decade, but a chance encounter leads to a ill-tempered meeting.

Annabelle Holmes, elder sister of Charlotte, is getting married but the bridegroom is missing and our heroes must solve the mystery to ensure the wedding goes ahead.
Meanwhile Watan is hired by Baron Zorkin, the Russian agent, to retrieve some valuable items but the investigation repeatedly collides with the priorities of the Holmes siblings.

Charlotte and Branwell must confront dark secrets, their mother's affair with their servant leads to unexpected revelations and the family must re-assess their perceptions of the past.
Durga is feeling restless and is demanding that Branwell, her secret lover, must provide her with a baby. However, his wife Rebecca, is profoundly against the notion, thus Branwell attempts to satisfy all parties by suggesting Watan oblige Durga.

Dark family secrets are revealed and brutal truths confronted in the opening book of the new arc; The Kensington Quartet .