Crisis - Nicky Perfect

We had been there for over 12 hours. The man was still 30 feet up a tree, balancing on a branch directly over one of the main railway lines out of one of the busiest train stations in the country. He refused to talk to us, threatening to jump if we came too close. To him, we were the enemy. My job was to preserve his life.

The most dangerous time in any negotiation is when you think you're winning.

From kidnappings to terrorist incidents, violent armed stand-offs to talking someone back from the ledge: all these make up the day-to-day life of Nicky Perfect's job as a crisis and hostage negotiator.

One of the first on the scene in situations that most would run from, Nicky is deployed to defuse the most volatile and fraught situations imaginable.

After a decade on the frontlines, confronting the extremes of human behaviour, these are the stories and cases that have shaped a career spent on high alert, where life often hangs in the balance. It's about finding yourself and following your passion, and of a life lived to help others.