"I'm so hopeless at all this," mutters Larry Lamb, as he jabs a finger at the screen of his smart phone. He is trying to book a taxi but it isn't going well. Lamb eventually admits defeat and hands his phone to a press officer, who quickly makes the necessary arrangements. He busies himself instead by pouring us both a cup of tea.

"I don't feel like an old man," says Lamb, who celebrates his 70th birthday in October, as he settles into an armchair in a central London office. "But the years are clicking on. I know I'm not going to live forever." Lamb is in a reflective mood. "I never realised that I was going to be old one day. I was about 65 when I thought, 'hang on, this is mortality now, I know there's a limit.'"

Old age and mortality: these are two of the central themes running through Lamb's latest project, The Hatton Garden Job. The film is based on the real-life, headline-grabbing heist, which took place over the Easter weekend in 2015, when a gang of wrinkly criminals with a combined age of 448 stole a reported 200 million of cash and valuables from London's jewellery and diamond district.