Luk Chi Lim (Louis Koo), an investigator in the Independent Commission Against Corruption (ICAC), is wrongly suspected of corruption. He must find a way to prove his innocence with the help of his friend, Lau Po-keung (Julian Cheung Chi-lam), a policeman, to find the potential mole. Meanwhile, Ching Tak-ming (Kevin Cheng Ka-wing), a member of the L Squad division of ICAC, investigates his case.

      L Storm is a suspenseful crime thriller with a terrific lead performance by Louis Koo. He has enough charisma to be make the character of Luk compelling and worth rooting for throughout the film. The screenplay by Man-lung Ho and Ho-Wah Wong has just the right balance of exposition, action, intrigue and much-needed levity. Too little exposition and the film would've become confusing and some of the beats wouldn't have landed; this isn't dry or dull like Tinker Tailor Soldier Spy after all. If there were too much exposition, the plot's momentum would've ground to a halt, so it's quite fortunate that there's enough exposition.

      You don't need to see Z Storm or S Storm to be able to comprehend the plot of L Storm. The less you know about the plot, the better, because it has some twists and turns along the way. Also, director David Lam should be commended for making a crime thriller for adults that's unflinching when it comes to its violence while avoiding cringe-inducing gore. He also maintains a fast pace with well-edited and choreographed action sequences. At a lean running time of just 90 minutes, L Storm is an intense, gritty and explosive crime thriller.