Plot hole: There must be a lot of dumb scientists in Sebastian's lab. While defibrillating the invisible gorilla, (s)he becomes completely visible for a moment. However, not once do the scientists consider that applying a mild electrical shock to the system renders the invisible animal visible again - that electricity may be the key to the whole invisibility problem. They don't even comment upon the fact that the gorilla does become visible.
Plot hole: Peter goes into Carl's mind to save Catherine. When he's in there he sees the tank with the water nymph. On the tank are strange symbols which provide the FBI with the clue needed to find the latest victim. Makes sense so far. But, go back to the scene just after the FBI have captured the comatose killer and are looking in his basement. The FBI are looking at the contraption that the killer uses to suspend himself over the victim. On the contraption is the same symbol seen later on the water nymph's tank. Why didn't the FBI follow up the symbol then?
Plot hole: In the makeshift morgue when Simon and Matthew first fight the vampires, Solina is shot and pinned to the wall with a large silver nail and remains calm and unaffected. However, moments later Marcus is fighting with Simon and grabs one of same kind of nails but must drop it when it burns his hands. It makes no sense that Solina had no adverse reaction to the nails at all when Marcus reacted so violently. (00:42:00 - 00:57:50)
Plot hole: Referring to that blackout night. How come the group can actually film how they put all their cameras and stuff into its hide?
Plot hole: When Alex and Clear are sitting and having coffee they are on a corner. He looks in the window to see the bus pass, and as he looks to see if it is there, it's not. As the camera pans across the street, there is some construction going on which is blocking that whole road from being used, but then Terry, Carter's girlfriend gets "waxed" by the bus - no way it could have got through all that construction.
Plot hole: Despite being whipped and needing to go to the hospice afterwards to have her wounds seen to, when we see Madeleine later in the film she doesn't act as though she had whiplashes across her shoulders - she lies on her back that very night in bed, and gets up without a wince, she holds her shawl close when she is wandering around the asylum, she leans back against chairs, and in all the later scenes she is still wearing her tight bodice, despite the fact that such wounds would have been very painful for ages afterwards.
Plot hole: After Nanahara and Noriko run away from Akamatsu at the school, Niida shows up from behind some bushes opposite the school and inadvertently kills Akamatsu with his crossbow. But Niida is Boy 16, which means he should still be in the school building (he's supposed to come out after Noriko, who's Girl 15). There's no way he has any time to get into those bushes.
Plot hole: After Jade sees Jaspers transform, she flees and calls the cop Margolies on his cell from a pay phone. It's pretty unlikely that in her panicked state of mind she'd remember his number by heart, especially since he only gave it to her that same day.
Plot hole: The scene where the sisters are talking about killing the popular girl in class during P.E. during a game of Lacrosse, Bridgette is pushed into the body of a disemboweled dog. Everyone then starts to freak out seeing the dead animal. How could anyone, the students, teachers, grounds-keeper, not see that corpse until Bridgette was knocked into firstname.lastname@example.org
Plot hole: How did Carolyn Fry get out of the cave in the canyon to confront Riddick at the Skiff? Riddick strained to roll the rock into the cave entrance, and he was a big, strong man from a position of good leverage. How did Carolyn and the other two push the rock out of the way so that Carolyn could get out? And, then, how did Carolyn mange to push the rock back into place? It was still there when she and Riddick came back from the Skiff to bring back the other two.Edwin Frydendall