On 25 November, The Mousetrap celebrated the seventieth anniversary of its opening in the Ambassador Theatre. For many years, Agatha Christie's theatrical masterpiece has held the record of the longest-running stage play in the world. It has been performed just under 29,000 times on the London stage and seen by over 10 million people. It led the West End out of lockdown; the first show to reopen now in its current home of St Martin's Theatre.

Royalties from the play were given by the queen of crime to her grandson, Mathew Pritchard. In 1995, Mathew set up the Colwinston charitable trust to support arts groups largely funded by those royalties. Each year, the trust distributes hundreds of thousands of pounds, with arts organisations in Wales receiving around 80 per cent of all grants. The trust has supported the National Museum of Wales, the National Eisteddfod, the Welsh National Opera, the Royal College of Music and Drama, and Welsh universities. It has also supported more local organisations and projects, particularly those benefitting children and young people or linked to improving access to the arts, like Valleys Kids. Seventieth birthday celebrations for The Mousetrap will include its Broadway debut and a tour around the UK, including performances in Cardiff and Swansea, and also a legacy of continuing to support the arts in Wales. Just remember to keep the secret locked.