The evacuation of an old apartment building in Taipei due to toxic contaminants is actually a ruse by a covert government-sponsored scientific team lead by Japanese Hashimoto (Yosuke Eguchi) who has developed the "Menger Sponge" made of human protein in order to achieve anti-gravity through the capture of electromagnetic wavelengths. Spraying ones eyes with the Menger Sponge material allows the viewer to see those wavelengths which include in the case of this building the ghost of a little boy. Spraying the apartment with the material, they are able to trap the ghost. They believe the ghost is just a remnant existing on an electromagnetic wavelength but the do not know why he hasn't dissipated. Taiwanese police officer Tung (Chang Chen) is recruited by Hashimoto's team because of his acute vision and lip-reading skills (demonstrated in an exciting opening set-piece) to find out who the ghost was, how he died, and where he is buried. They allow the ghost to exit the apartment and Tung tracks the ghost on what turns out to be a daily re-enactment of his death and discovers that the boy suffered from a disfiguring disease and tried to kill himself before disappearing with his unbalanced mother. Tung, however, discovers that the ghost is more than just an impression and is in fact dangerous (during a grisly autopsy of a spirit photographer who supposedly had a heart attack, Tung discovers the impression of fingermarks the size of a child's hand around the victim's heart) and conscious of their observations of him. With the Menger Sponge, Tung is able to see a solidified strand of silk that connects the ghost to his future victims and that Hashimoto is more interested in the ghost's persistence than anti-gravity but the team, Tung himself, and his girlfriend have already been targeted by the ghost.

The critical hyperbole on Tartan's DVD cover refers to it as possessing the "realism of WHITE NOISE with the sheer terror of THE EYE." While the film does make use of the usual long-haired women and creepy ghost children as well as the usual digital effects, SILK is putting a new spin on the genre with a plot that extends beyond the usual "find the corpse to free the spirit, oh wait, it's not over yet and is far more complicated than that" that mars most post-RINGU/GRUDGE Asian horror movies (then again, it may not seem so to viewers approaching these one at a time compared to a reviewer with a stack of these on his desk) such as the thriller/ghost hybrid ARANG. While it does not quite surpass the chilling set-pieces of the otherwise overrated THE EYE, it is more successful than WHITE NOISE both in its plotting of the scientific investigation into the supernatural and in hitting the emotional notes. The scenes with Tung and his sick mother and the toll her sickness takes on his relationship with his girlfriend Wei (who believes that skilled but emotionally numb Tung is afraid of living his own life) are much more effectively realized than the crippled Hasimoto's envy of the ghost boy's existence apart from the rest of the world (the cutting of the film's superior alternate ending - included in the extras - renders the film ambiguous but also undercuts Hashimoto's character development). While there is nothing new in the scares department for seasoned "Asian horror" viewers, the plot and its treatment (including a tense, action-film opening that works) makes it worth a viewing.