Hall, Crawley Grange, Wavendon House and Gayhurst Manor, were all taken over by Bletchley in 1942. Soon the authorities were forced to look further afield, creating a custom-built site capable of housing more than 60 Bombes and 600 Wrens at Stanmore, north of London. The need for more staff to run the Bombes was acute and the authorities began to advertise for Wrens ‘for interesting and extremely important work . . . necessitating the operating of light electrical machinery. Girls should be of good physique and education, quick, accurate and keen, with good powers of concentration.’ Colette St George-Yorke became a Wren in October 1943 when just seventeen and a half, the earliest age at which you could join up. Colette had been brought up in Harrogate in Yorkshire and went to the local convent school. Her father was a timber merchant, but because of the war the government had taken over all the buying and selling of timber and he was working for the Ministry of Aircraft Production. When Colette left school she was mad keen on becoming a Wren but she was only sixteen and had to do something else until she was old enough to join up. ‘The chap who lived next door to us in Harrogate was the managing director of the Yorkshire Dyeware and Chemical Company in Leeds and he said there was a job for me. I could be a lab assistant. So I was there for a year until I was seventeen and a half and could officially apply to join the Wrens.’ Colette signed up and was given a medical and sent home. A couple of weeks later she was called forward to the training and drafting depot at Mill Hill. ‘And I thought it was absolutely marvellous. They had a quarterdeck and a white ensign. You couldn’t walk across the quarterdeck. You had to go at the double. If you went across the quarterdeck you had to salute the white ensign.’ The Wrens were organised into different divisions, each given the name of a famous naval hero. Colette was in Howe Division, named after the eighteenth-century Admiral of the Fleet Richard Howe who defeated the French at the Battle of the Glorious First of June. The young Wrens had two weeks of training as a probationer,during which time they wore navy blue overalls and could leave if they didn’t like it. Colette was told she wouldn’t be given the smart navy blue uniform she’d joined up to wear until the third and final week of training, once she’d committed to staying in the Wrens. ‘They got us up in the morning at half past four with a klaxon and we used to have to scrub the floor of the corridor and then we would have a great big mug of tea and some bread and dripping. I thought this was fantastic. And I made friends with a girl there who came from Yorkshire as well, Sheila Tong. Anyway, eventually we were called up for an interview on what we were going to do. There were only three categories left: cooks, stewards, or Pembroke Five.’ Pembroke merely indicated it was a shore station – at that stage Wrens weren’t allowed to serve on board ships – but it didn’t tell them anything about what the job was. The two girls looked at each other and then at the petty officer who was advising them. ‘What’s Pembroke Five?’ ‘Can’t tell you.’ ‘Ooh, that sounds interesting. We’ll do that.’ They spent another two weeks at Mill Hill, having to wait long after everyone else on their draft had been posted away because they needed to be vetted to make sure they weren’t a security risk. ‘Finally the day came when we were given our uniforms. We got into a coach and off we went. I can remember Sheila saying, “Isn’t this exciting. I wonder where we’re going.”’ About twenty minutes later they pulled into anothernew Bombe base at Eastcote, just ten miles west of Mill Hill. It was a depressing anticlimax. This was the secret base? They’d been hoping for some sort of top-secret intelligence organisation hidden away and they’d ended up at a muddy building