Half way through it.
I don't know if the serialisations published have covered the reasons for his leaving but basically he didn't sign his contract because he was waiting on an assurance from the Club that would apply to the RFL for his testimonial. The letter he requested never came and therefore he didn't sign the contract; this was the root cause of the resentment between him and the Club. The testimonial couldn't be written into the contract because then it would be liable for income tax and Cooke and his father (who acted as his agent) were adamant on requiring this 'letter of comfort' I think they called it.
It is interesting what he says about John Kear. Kearney, when he left, wrote an appraisal of the Club and that was pretty damning on the state of the club and player development. According to Cooke, Kearney said that players were pretty much left to get on with it and that he and Horney needed specialist coaching to develop their game which they just didn't receive.