Twenty-five years ago in Hong Kong, a wealthy businessman had just seen work completed on the Victoria Harbour Tunnel which connected the island to the mainland. After attending the opening ceremony, he was driving back home with his wife and twin boys when he noticed he was being followed, and phoned his right hand man Frank Avery (Geoffrey Lewis) who told him not to get out of the car, and he'd be there as quickly as possible. Drawing up at their home, the businessman found himself subjected to a hail of bullets from a group of heavies - both he and his wife would die, but Frank arrived just in time to save the babies...
And those babies grow up to be Jean-Claude Van Damme and Jean Claude Van Damme! Yes, two Van Damme's for the price of one, as Double Impact was co-scripted by the star to show off his thespian talents as well as his martial arts skills. In fact, the emphasis seems to have been on the acting rather than the fighting, as it was not exactly the most unarmed combat concentrated entry into the canon of the Muscles from Brussels, which is down to him apparently deciding that the best co-star he could ever have would be his own good self. But first the two twins, separated all these years, have to meet up again, which thankfully doesn't take up much of the running time: well, why make us wait?
Twin one, Chad, is a keep fit instructor in America, giving him the excuse to do the splits within about five seconds of appearing on the screen. He is mentored by Frankie who he believes to be his uncle, but now the time has come for him to reveal the truth about his background and head back to Hong Kong. All to avenge the deaths of his parents, or that's what we think at the start, as by the end who knows what the point was? For a plot that starts out with a straightforward vengeance idea, it doesn't half grow obscure about the details of why the brothers are getting back at the bad guys, who include the evil businessman Griffith (Alan Scarfe) who ordered the deaths of their parents.
Anyway, mistaken identity provides much of the tensions and humour as the pink shorts-clad Chad wanders into a bar in Hong Kong and is thought to be Alex, his long lost brother, complete with Alex's girlfriend Danielle (Alonna Shaw) trying to seduce him until she realises her error. We can tell them apart because there's no way the cigar-chomping Alex would wear pink shorts (or "black silk underwear", for that matter), as he is a tough guy, whereas Chad is more in touch with his feminine side, leaving enormous scope for Van Damme to essay two markedly different interpretations, sort of a ying and yang if you like. Well, actually the only way you can tell them apart is that one has his hair slicked back and the other doesn't.
Naturally, there is antagonism between the siblings, to the point that Alex thinks his twin is trying to win Danielle away from him, which leads to a sequence where he imagines them making love as he gets drunk, although with the regard that Van Damme apparently has for himself here it would be more convincing if he was imagining a love scene with himself - he has a fight scene with himself after all. Notable amongst the villains is Bolo Yeung, who may not have fought Bruce Lee in Enter the Dragon, but does get to go head to head (or foot to head) with Van Damme here in one of the edited too quickly setpieces. Add in a good few explosions and a huge amount of gunfire and you have the cinematic equivalent of grown men playing a game of cowboys and Indians, all slathered with "I'm taking this very seriously" cheese from the leading man. Music by Arthur Kempel.