Ross Kemp tells the untold story of the police investigation into the Hatton Garden Heist – Britain's biggest burglary. Interviewing key officers, and using unseen police surveillance footage and the gang's secretly recorded conversations the film takes us inside one of the Flying Squad's longest and most challenging operations, ending in the conviction of the final gang member in April this year. As well revealing the inner workings of the investigation, the film sheds new light on the gang themselves with the first ever TV interview with Kenny Collins – the gang's lookout – as he tells the inside story of the burglary and their conviction for the very first time.