There are many cultures that give extra meaning into getting a tattoo. Many of them say that the actual tattoo has magical power or the process of getting tattooed has inherent power. "Ink" is a story based on that theme, and a bit more. Such as the scary thought of the substance that you are getting tattooed with may not necessarily be just ink.
An ancient evil once defeated and imprisoned has returned. Can our reluctant hero and the small band of helpers come together to defeat it, and once more contain it?
Remember, even those reluctantly chosen to be heroes are nonetheless still heroes. Even if they don't believe it themselves or even know it yet.
The prison and its contents were forgotten and eventually became lost through time, however as it is with such things, it was eventually found and soon opened. The creature once more released began to kill and feed again. It discovered this modern new world was well suited to feed its thirst.