f you grew up reading The Famous Five and The Secret Seven, it’s easy to feel that summer holidays aren’t what they used to be. For most children, the only mysteries to solve are who had the last lolly from the freezer and, come September, just where those six weeks went. This year, lockdown restrictions and cancelled travel plans have narrowed horizons for little adventurers. So it’s a delight and a relief to take delivery of what promises to be a “seven-day theatrical experience” for families to enjoy at home. Created by Huddersfield’s Lawrence Batley theatre, The Dukes in Lancaster and theatre producers The Big Tiny, Charlotte Holmes is billed as an adventure box. When we open up our package it feels like Christmas has come early: inside are brightly coloured envelopes and lumpy parcels wrapped in different materials. Aggie (10) and Hilda (six) detect a magnifying glass in one and a bottle in another. These exhibits, and the instructions in each envelope, will lead us through four mysteries encountered by Charlotte, a young girl evacuated to Yorkshire during the second world war. Aggie loves Robin Stevens’ Murder Most Unladylike series but the mysteries here are more to do with missing jewellery, pilfered biscuits and Charlotte’s own identity. Still, there’s a Cluedo-like cast of characters in Charlotte’s temporary home, the grand Batley Hall: suave Sir Jeremy, cranky butler Alfred, nervous maid Alice and no-nonsense cook Mrs Mirfield. They are played by actors in jaunty online videos, performed against brightly illustrated backdrops, that work in tandem with the contents of the box. (Pupaphobes beware: Hilda hides behind her hands during the Punch and Judy video.) The idea is to open an envelope a day, which gives you an activity that is integral to the story but can be enjoyed separately. So a guidebook to British birds may contain a clue but could also be taken to the park. A mock 1940 newspaper develops the characters but also has a crossword. A deck of cards deepens the mystery but we’re taught a number of games to play with them. Most envelopes contain a piece to a jigsaw that, once completed, will help solve a larger puzzle. The experience is designed for children aged seven to 12. Hilda takes control of our jigsaw and enjoys the dot-to-dot puzzles, Aggie tries some Bletchley Park-style code-cracking. Adults’ little grey cells are required too; it took the efforts of all four of us to solve the cases. It’s so ingenious and intriguing (and, frankly, too hot to be doing anything else) that we can’t resist racing ahead, and we rush through it in two days. This is not to be advised – our teamwork soon evaporates as we’re grabbing clues from each other and arguing over who to accuse. Best let the activities breathe and get as much fun as you can from it all. What’s consistently apparent is not just the attention to detail in the plotting but a sense that the creators have really considered the emotional toll of lockdown on children. Gently, the game opens up the outside world to kids once more and encourages them to express themselves. By the end, we’re surrounded by a bottle’s worth of unspooled, pastel-coloured messages, lying alongside dot-to-dot drawings, torn envelopes, scattered cards and Enigma codes. As one of the messages says: “There’s no use keeping everything bottled up”.