Reynir has just finished eight weeks at Paramedic College and has just begun three years of on - road training. It's his second day with new mentor, veteran paramedic Mel and within minutes of starting his shift, Reynir is thrown into the deepest end possible. In Sydney's Central Railway station a businessman is about to make a huge impact on the young trainee. As the man walks to a train, security cameras capture him collapsing to the ground - he's had a heart attack. Minutes later a team of paramedics, including Reynir, rush to treat the man. It's Reynir's first cardiac arrest and the first time he has used a defibrillator in a real life situation. Only 3 percent of people who suffer cardiac arrest outside hospital survive. If the man does pull through he'll be one of the lucky few. At the end of three months on-road training, it's time for Jenna, Evan, Rebecca and John to say goodbye to their first mentor. They've all faced and surmounted many challenges and over the next three years many more will follow. But for now it's thank you's and fond farewells for those mentors that got them through the first moments of paramedic life.