JS Cheung (Andy Lau) was working undercover a year and a half ago with a gang who were planning a heist on one of Hong Kong's biggest banks. He is a bomb disposal expert, but that also means he knows how to construct an explosive device which is what he had been doing for the gang, much to the approval of its leader Peng Hong (Jiang Wu) who saw to it that Cheung and his own brother, Biao (Leo Zi-yi Wang) were at the forefront of this robbery which went very well, the gang getting away with an absolute fortune. Or at least they did until Cheung decided enough was enough and he was not about to place his fellow police officers in danger, and proceeded to end the pursuit with bullets.
Now, Peng gets away, but his brother is arrested (as are many others of the criminals), and what do you know he is definitely one to bear a grudge, which was handy for screenwriter Erica Li, working with director Herman Yau, since they wouldn't have much of a plot without that impulse to get even. Yau was probably still best known for his nineteen-nineties thriller Ebola Syndrome in the West, but he had been a busy bee between then and this, which became his highest profile release across the globe thanks to presenting old reliable Andy Lau in his action hero role, demonstrating old action stars never die, they never even retire, they just keep plugging away at the coal face of guns 'n' explosions.
Lau was in his fifties when he made this, younger than some of the action exponents still carrying on in spite of the moves not being as impressive as they once were, and a slight air of rustiness setting in to their specially tailored vehicles. But it was cheering to say this was one of his best parts in some time, as he got to show off his range from a romantic sequence or two with his new, schoolteacher girlfriend Carmen (Song Jia) to playing the badass who could possibly save the day when Peng gets his schemes into gear. Some films would have dispensed with the opening half hour of character establishment, and it did seem a shade superfluous once the business in the tunnel got going.
But Yau evidently wanted to offer value for money, therefore we were served the full two hours, a three-course meal of thriller with added drama and plenty of over the top pyrotechnics. Peng's big idea is to place a truck packed with explosives at either end of the Kowloon Tunnel, and force those unlucky enough to be drivers and passengers there when he does so to be his hostages. His demands are mostly monetary - but he also wants Biao released into his care, which is complicated when it becomes clear his brother truly resents him for turning him to a life of crime and wants nothing more to do with him. Even further complications occur when Biao is seriously injured and in semi-farcical scenes is forced to attend the tunnel on a stretcher, almost completely paralysed, but that's not the half of it.
To prevent the army of cops trying to scupper his plans, Peng sets up various obstacles to keep them occupied and unsure of what his next move may be. Wu proved a smug villain, smug enough to have you want to see his grand orchestrations crashing down around his ears, though not the tunnel itself doing the same. Cheung finds this is personal because Peng remembers all too well his betrayal, making this reminiscent of Die Hard with a Vengeance, or perhaps a variant on The Dark Knight as the film makes it clear society is a few short steps away from anarchy should someone determined enough pull the strings and send the community toppling into calamity - there was a note of the seventies disaster movie here too, with the location of the tunnel ideal for a spot of soap opera to offset the impending doom. To say more would be to give away too much, but suffice to say, no matter the occasional illogicality in service to ramping up the tension, Shock Wave was a very decent experience in action cinema, and proved there was life in Hong Kong's signature genre yet. Music by Mak Jan Hung.