Hook, line and sinker

As well as the mind-blowing action sequences, the new film also aims to explore the complexity of humanity, says Lam, who assigned his scriptwriters to interview rescuers and document their words.

"One of my most impressive tales was from a rescuer who had to go out on a mission on the day that his father passed away. He was in shock from grief, but he said it was his duty to hurry to the scene to help people in need," recalls the emotional director.

"For me, it's interesting to discover that a hero who battles nature could also be the sort of ordinary person who lives next door. He could be a caring father or a concerned husband, but in a minute, he has the ability to transform himself into a fearless hero," says Lam.

A native who entered Hong Kong cinema during its golden era in the 1980s, Lam shot to fame from alongside Gordon Chan for codirecting the award-winning Beast Cop (1998), and he grew his reputation on the Chinese mainland with the success of Beast Stalker in 2008.

Now considered as a master of action films, Lam has shot epics set in the air, on the ocean and underwater. When asked what kind of place would spawn his next adventure, the director smiles. "I don't dare to think. I'm afraid that I wouldn't get (the go-ahead) to shoot such a film even if I had a great idea.

"For people like me, we just love cinema, and the process of shooting a film is enjoyable in itself," says Lam.