"Over two months, I slept an average of three hours each day. When the schedule included scenes for my role, I didn't even remove my makeup to catch a bit more sleep, around 40 minutes, overnight," recalls Qi.

In the final scene, the police officer ultimately finds his archenemy — the spy — 19 years later. The climax takes place on a cruise ship, amid a bustling tourist crowd, where the gazes of the two men transcend the vicissitudes of time, entangled in indescribable complex emotions.

This scene is somewhat regretful to the director because he initially hoped to film it on a two-story ferry for more action scenes but had to condense three days' worth of work into a single day.

Despite the hardships and difficulties, Qi says he cherishes the opportunity to produce The Silent Storm, which he believes depicts a rarely explored theme paying tribute to the heroes of the Ministry of State Security.

"In one of my early interviews, I asked the wife of a national security officer if she worried about her husband's safety during missions. Her response struck me deeply as she answered, 'I don't even know when he's out on a task'. That really got to me. It's because of countless unsung heroes like Wu, the protagonist, risking their lives and selflessly serving on the battlefield without gunfire, that our country stays safe today," says the director.