The Twins Effect is an action-comedy about a couple of vampire-killing cuties, with timeouts for comedy and romance, some kickass kung-fu choreography by Donnie Yen, and a mega-publicized cameo by Jackie Chan. The Twins and associated other properties (Ekin Cheng, Edison Chen, etc.). Hong Kong's highest-grossing film of Summer 2003. The fighting contains obvious wirework, the acting is full of egregious highs and the film's comedy can be unfunny and even sophomoric.

Apparently, there is a "League" of elite vampire hunters who rely on vampire blood to provide them with the power to take down the undead. Among them is Reeve (Ekin Cheng), a dashing hunter who loses his partner/lover Josie Ho in the film's opening moments. Depressed, he vows never to fall in love with his partner again. Sudden idea: why not get a male partner?

Meanwhile, vampire royalty Prince Kazaf (Edison Chen) moves into a church somewhere in Hong Kong with attendant Prada (Anthony Wong). There's apparently some inter-clan vampire strife going on back in vampireland. Kazaf happens to be a good vampire, who only drinks blood from bottles, and doesn't suck from the necks of victims. Never mind that the blood had to come from somewhere (Kazaf's royal dad probably does the killing and bottles the brew), Kazaf is a character to be liked and sympathized with. He's nice, sleeps in a dope tricked-out coffin, and is played by Edison Chen. That mean's he's totally hot and ultra-sensitive to the needs of teenybopper-type girls everywhere. If all vampires looked like Edison Chen, victims would be beating the door down to get to him. And with that set up, enter the main attraction: two pint-sized popstars with more spunk and cuddliness than should be humanly possible.

Helen, sister of the vampire stalker Reeve, depressed and a wacky sort of a girl. Luckily she meets Kazaf, who immediately takes a shine to her. The two begin an odd courtship, hampered by the fact that Kazaf is suspiciously averse to sunlight and has other odd habits like drinking blood. Will helen know Kazaf is a vampire???

Gypsy signs up to work with the dashing Reeve because he's the hottest vampire hunter around, besides, he has amazing hair. Gypsy tend to Reeve's every need, i.e. cleaning, cooking, and acting like little Missy Homemaker. It could be every young man's dream.

The major for the girls will one day team up to fight vampires themselves, which promises for major buttkicking and wirework courtesy of Donnie Yen. This plotline proves to the "important" one, as an evil western vampire shows up in Hong Kong to snake Kazaf's hide. Apparently, taking out the hottest vampire ever is the only way to lay one's hands on "Day for Night", an ancient book which gives great power, or something like that.

Ekin Cheng is likable and self-effacing as the "old" popstar, and Anthony Wong and Josie Ho manage their small parts well. Jackie Chan's cameo is more than a little out-of-place, and probably could have been done away with, but there's some amusement to his minor turn as a harried groom, which is made all the more fun thanks to a cameo from Karen Mok as the bride. The good-natured silliness of the whole affair proves somewhat charming, such that the bad screenwriting, disjointed plotting, annoying music, egregious supporting actors, and even Edison Chen don't seem to hurt much.