Jamie Campbell Bower Lily CollinsSony

School's back in session for half of the country, but there's one more big offering for the teens this late August: "The Mortal Instruments: City of Bones." Based on author Cassandra Clare's extremely popular book series, the story follows Clary Fray (Lily Collins), a New York City teenager, who on the eve of her Sixteenth birthday discovers some unbelievable things, like the fact that her mother (Lena Headey) -- who has been abducted -- is really a former Shadowhunter, a covert group of demon slayers who've pledged to protect the world from creatures of darkness. On the bright side, there's a hunky blond Shadowhunter named Jace (Jamie Campbell Bower) who offers to help Clary navigate the supernatural world hidden around the city in order to find her mom.

Here are five issues to consider when deciding if "City of Bones" is a good fit for your family.

1. How sensitive is your kid to violence? At more than two hours long, the movie features several long action sequences that include moments of torture, demonic possession, and even deaths. Clary's mom is abducted and held hostage; there are battles between the Shadowhunters and vampires (as well as the ubiquitous demons), and a couple of cringe-worthy demons that emerge out of their hosts. One important character nearly dies, and there's a whole lot of sword wielding and knife throwing. Plus, a villain fights his own biological children.

2. Do you want them to "Read It, Then See It"? Teens well versed in young adult urban fantasies have probably already heard of Cassandra Clare's best-selling novels -- either "The Mortal Instruments" or its equally as popular companion series set in Victorian England, "The Infernal Devices." If they haven't read the books yet, it's a perfect time to add the franchise to their To Be Read list. Clare's world building is elaborate, and the characters in her novels are heroic and funny and unlike many comparable protagonists, mortal (well, for the most part). Fast and romantic reads, the books follow beautiful but flawed characters that teenagers will feel invested in for six books (the final installment, "City of Heavenly Fire," comes out in May, 2014).

3. Do you worry about sex/language? Most teens curse, but not so much in this movie; there's actually less language in the adaptation than I remember in the books. And as for sex, there are plenty of sexy actors and suggestive references, like when a shirtless and boxer briefs-clad Magnus Bane (the gorgeous Godfrey Gao) basically purrs at the closeted Alec (the also ridiculously attractive Kevin Zegers) or when Jace accuses Clary of having another guy in his bed, when in fact it was just her platonic BFF. At one point Clary wears one of Isabelle's tight outfits, which is so short she says, "This is a shirt not a dress." Of course there is the one climactic kiss in the greenhouse, accompanied by a pop ballad, the literal blossoming of flowers, and even a perfectly timed sprinkler. After all, things don't get really hot and heavy until the third book.

4. Who will enjoy the movie most? Obviously followers of Cassandra Clare's "The Mortal Instruments" books will enjoy the movie most -- and may be the only ones in the audience who fully understand the plot, which is harder to follow (and less exciting) for those who haven't read the books. The movie's supernatural universe and twisty paradigm shifts (not to mention a last-minute allusion to a possibly incestuous connection between the two central characters) will make perfect sense to moviegoers familiar with the series. Fans of Jamie Campbell Bower's previous work in franchises like "Twilight" and "Harry Potter," or Robert Sheehan's brilliant stint on the UK series "Misfits" will also want to see the British actors on screen.

5. What are critics saying about "City of Bones"? Reviews for the mid-week release have been relatively underwhelming with a score of 33 on both Metacritic and Rotten Tomatoes. But some of the more positive reviews admit it will play well among fans of the books or the genre of teen fantasies: "There are elements worth celebrating. The movie is thankfully less self-serious than the mopey "Twilight" films. 'The Mortal Instruments' revels in its own camp. But there is plenty of room for improvement," says Stephanie Merry, "The Washington Post." Colin Covert of "The Minneapolis Star Tribune" writes, "With its spectacle, morbid sense of humor and hustling pace, 'The Mortal Instruments' encourages you to shrug and just go with it.

Mortal Instruments City of Bones Movie Preview
The Mortal Instruments: City of Bones Movie Poster
The Mortal Instruments: City of Bones
Based on 35 critics

In New York City, a seemingly ordinary teenager named Clary Fray (Lily Collins) learns that she is descended... Read More