Soo-na is a beautiful tattoo artist who possesses the unique skill of being able to perform the rare “stitchery tattoo” that uses needle and thread. This style of tattoo is very painful and she prefers not to do it this way. She also has a habit of mixing in some snake venom into the ink she uses for tattooing. This can cause some interesting and sometimes lethal side-effects whenever her clients are in the heat of passion. In other words, you do not want to mess with Soo-na. Now she has a new client, Ji-soon, who is very persistent in wanting her to use the stitchery tattoo technique. Soo-na gives in and agrees to finish the tattoo of a Medusa on his back. She quickly learns that behind the Medusa lies a dark secret that has ties to her own past. What follows is a tale of revenge, murder, and tattoos.