The Case of the Cryptic Crinoline

The penultimate book in the series tones it down a bit, cutting back on the swinging from the roof fittings and other Errol Flynn style shenanigans. Instead Enola relies on her usual considerable talent for disguise, sketch making, cryptology and of course her endless supply of pluck.
In her hunt to recover her kidnapped landlady she is forced to consult Florence Nightingale, which, teachers take note, means the Crimean War is a part of the story. This series is fun for kids and if the spark of interest in history is fanned then so much the better. Barring casting Florence as a spy the author respects the historical accuracy of the historical figure.
One of the better additions to the series.