The Ministry of Unladylike Activity Books in Order

The Ministry of Unladylike Activity series moves the world of Wells and Wong forward into the Second World War. Set in the early 1940s, it imagines a secret British government department that quietly recruits children as spies, on the assumption that adults will underestimate them and never think to listen in on what they overhear.

At the centre is May Wong, Hazel's quick-tempered younger sister. Left in England while most of her family are in Hong Kong, May is desperate to prove herself useful and furious at being treated as a child. When she and clever refugee Eric Schlossbauer are turned away from the Ministry's London offices, they decide to carry out their own mission anyway, certain that if they succeed the grown-ups will have to take them seriously.

In the first book, The Ministry of Unladylike Activity, May and Eric pose as evacuees to infiltrate grand Elysium Hall, home of the wealthy Verey family and their Irish-American relative Nuala. Hidden among rationing, blackouts and suspicious servants, they suspect that someone in the house is passing information to Germany. Before long, secrets multiply, alliances shift and a murder forces the three new friends to become real investigators rather than would-be spies.

Later stories such as The Body in the Blitz and A Stocking Full of Spies widen the canvas. May, Eric and Nuala dig into the secrets of a seemingly quiet London street, pick through the rubble of bombed-out houses and, eventually, travel to Bletchley Park, where Hazel now works cracking codes. Familiar names from the Wells and Wong novels reappear in new roles, tying the girls' earlier school adventures to the larger, more dangerous world of wartime intelligence.

Although the stakes are higher and the backdrop darker than at Deepdean, the Ministry books keep the same puzzle-box structure as the original series. Each case offers a trail of clues to follow, suspects to test and codes to crack, alongside the everyday worries of growing up in a time of blackout curtains, ration cards and missing relatives.

For readers who have grown up with Daisy and Hazel, these novels feel like the natural next step: the mysteries are still fun and fair, but they also ask what it means to take risks, make mistakes and try to do the right thing when the whole world seems to be at war.