Lily Collins stars as Clary, a teen who discovers that her mother (Lena Headey) is secretly a Shadowhunter, a hunter of demons. At the same time as her mom is kidnapped, Clary, a bright redhead, realizes she's able to see a hidden world in their native New York, one where Shadowhunters, demons, werewolves and warlocks stealthily operate in varying degrees of gothic drab, invisible to humans, or "mundanes."

It's a lot like a mediocre episode of Buffy the Vampire Slayer.

As she hunts for her mom, Clary is quickly indoctrinated into this underworld, led into it by the aforementioned heartthrob, Jace (Jamie Campbell Bower), an alluring Shadowhunter with blond locks.

Directing from Jessica Postigo's overstuffed screenplay, Harald Zwart (the Karate Kid remake) summons the kind of dingy, baroque, nighttime atmosphere that Jonathan Rhys Meyers revels in. As if falling for the trap, he reliably turns up to lend his pallor to the proceedings as the villain Valentine. He's seeking a magical cup that Clary might — if she can stir the memories her mother had tried to block — know the location of.

The plot is astonishingly overcooked: a mishmash of watery portals, Greek-styled father-son drama, invisible buildings and supernatural battle lines. It reaches an apogee of ridiculousness when, we are informed, Bach was a Shadowhunter, whose compositions were designed to ward off demons.