After Ryan was sentenced to Pentridge Prison, he was placed in B Division where he met fellow prisoner Peter John Walker (who was serving a 12-year sentence for bank robbery). When Ryan was informed that his wife was seeking a divorce, he made a plan to escape from prison. Walker decided to go along with him. Ryan planned to take himself and his family and flee to Brazil, which did not have an extradition treaty with Australia. At around 2:07 pm on Sunday, 19 December 1965, Ryan and Walker put the escape plan into effect. As prison officers were taking turns attending a staff Christmas party in the officers' mess hall, Ryan and Walker scaled a five-metre prison wall with the aid of two wooden benches, a hook and blankets. Running along the top of the wall to a prison watchtower, they overpowered prison warder Helmut Lange and took his M1 carbine. Ryan threatened Lange and demanded he pull the lever to open the prison tower gate. Lange, however, deliberately pulled the wrong lever. Ryan, Walker and Lange then proceeded down the steps to the tower gate, but it would not open. At the bottom of the stairs was the night officers' lodge. Warder Fred Brown was returning from lunch to relieve Lange when he was confronted by the escapees. Brown did not resist. When Ryan realised Lange had tricked him, he jabbed the rifle into Lange's back and marched him back up the stairs so Lange could pull the correct lever to open the tower gate. The two escapees then exited through the gate into the prison car park. To the escapees' dismay there were only two cars in the car park and one had a flat tyre.