There is a website called kids-in-mind, that actually itemizes and describes the more questionable parts of movies, so that parents can decide if they want to let their kids see it or not. I have found it very useful. I just read the (horrific) description of TDK. If you want to read it too, to prepare yourself, or to know if these are images you want seared into your or your kids' heads, the link is below. It doesn't describe the plot, but it does simply and literally describe the violent moments.
For a sample of kids-in-mind, here is how they describe the violence/gore in BBM. (They rate BBM a 6 out of 10 in violence/gore, which seems crazy, because from the description of TDK, it is far, far, far worse, and it got a 7 out of 10.)
BROKEBACK MOUNTAIN VIOLENCE/GORE 6 - A man is beaten by three men with clubs (we see his very bloody face and it is implied that he was beaten to death). A man talks about another man being beaten by a mob with a tire iron and then dragged around by his genitals until "they fell off" and we see a boy (the man when he was a child) looking at a bloody and battered dead man.
► Two men make crude sexual remarks at a public gathering, and another man tells them to stop; they persist, the man punches one of them in the face (we see him with a bloody nose) and kicks the other in the head. Two men wrestle and fight, one punches the other in the face (he has a bloody nose) and the other punches the other in the face too (he has a black eye). A man is nearly hit by a car, he punches the driver of the car twice, the driver gets out of the car and he punches the man several times while he is lying on the street (we see some blood on his face). A man gags, cries and punches a wall when he and another man part company.
► A man shoots an elk, it recoils when it is hit, it stumbles and falls to the ground, and we then see two men cooking and eating its meat and there are other pieces of meat hanging to dry. A man finds a dead and bloody sheep with its chest and abdominal cavity open and bones and organs visible.
► A man is thrown off his horse when it rears after seeing a bear; the man runs after the horse and appears to be limping. A man shoots a gun at a wolf prowling around a herd of sheep.
► A woman confronts her ex-husband about an affair that she suspects he had (with another man); he yells and raises his fist, she screams and he leaves. A husband and wife argue and yell at each other. A man yells at another man and threatens to hit him. Two men yell at each other and argue.
► We hear that a man was killed when a tire on his car blew up, the hubcap hit him in the face knocking him unconscious, and he drowned in his own blood.
► A man talks about his parents having died when he was young and that he was raised by his brother and sister. A man talks about a lightning storm having killed 42 sheep and that the smell nearly asphyxiated him.
► Two men are pelted by large hail during a storm. We see children playing with firecrackers (no one is injured). A man holds a young sheep and pulls something out of its leg (like a thorn or a burr). A man urinates in the background (we don't see or hear anything).
Okay, so here is the link to the kids-in-mind page about The Dark Knight. I am glad I read it - I am stunned that I am about to knowingly go tomorrow to watch a movie with so much brutality and sadism. But what we do for love....
http://www.kids-in-mind.com/d/darkknight.htm
