JOHN OBI MIKEL stared at the briefcase bulging with $70,000 (£53,000) in cash. The agent then made his offer: “Sign here and this money is yours.” Mikel was just 15 years old and this was the start of the craziest transfer battle the game has ever known. It resulted in Sir Alex Ferguson and Jose Mourinho scrapping to sign him — and ended with Chelsea paying Manchester United £12MILLION in compensation. The ex-Blues midfielder finally revealed the truth behind the incredible squabble for his signature and how: He was whisked away in a James Bond-style operation involving decoy cars to a secret meeting at then Chelsea boss Mourinho’s house. United offered him a staggering £1.5million contract even though he had only just left school. He twice said ‘No’ to Fergie in two secret face-to-face meetings. He had an emotional heart-to-heart with Premier League chairman Sir Dave Richards to try to end the conflict. Barcelona then tried to hijack his move to Stamford Bridge. Mikel admitted: “It was surreal. I was at school, but had Chelsea and Manchester United — two of the world’s biggest clubs — trying to sign me.”I’ll never forget that second meeting with Sir Alex. I’d signed…