Corpse at the Crystal Palace/Carola Dunn

Daisy Dalrymple Fletcher takes her two young cousins and their nanny, Gilpin, to see the Crystal Palace. Gilpin goes missing and the dead body of another woman in nanny garb is found, and when Gilpin is located she is chasing after another nanny before becoming unconscious with no recollection. A 1920s cosy crime with all of the period detail fans of the series enjoy.