Now that Sex and the City has drained its last cosmopolitan, where can fans of smart, savvy entertainment go for their fix of stories about the trials and tribulations of four girlfriends? Why, to the Sisterhood of the Traveling Pants series, of course!

Don’t let the young adult trappings fool you. These novels can be enjoyed by readers of all ages. (Although if you’re looking for the ribaldry of the aforementioned HBO series, you’re out of luck.) Ann Brashares’s latest entry in the series arrives with much fanfare, with news of a Sisterhood movie arriving this summer, a 10-city book tour, and even a contest among readers to answer the question “What would you do if you were about to be separated from your three best friends?” (echoing the plot of the book). But does it live up to the hype?

Uh, sort of. Girls in Pants: The Third Summer of the Sisterhood is better than the original, The Sisterhood of the Traveling Pants (which, weirdly, isn’t even that great—simply average) but falls short of the first sequel, The Second Summer of the Sisterhood, which is a masterpiece. (Yes, I used the word “masterpiece” to describe what is essentially a children’s book. What’s it to ya?)

The series gets its title from a magical pair of jeans that Lena’s sister, Effie, rescued from thrift-store obscurity back in the prologue of book one. Although the girls are all different shapes and body sizes, the jeans fit each one of them, making them feel loved and connected even when they are spending their summers apart. They use the pants as armor to protect them from all of life’s injustices—such as insensitive parents, unfaithful boys, and tragedies from the past that they thought they had forgotten.

The plot of Girls in Pants is both simpler and more complex than its predecessors. In others words, there’s more going on—the four main characters prepare for college, and three of them each receive a new love interest—but emotionally, the proceedings feel sparse. Brashares needs to stop developing new characters and instead concern herself with the girls of the Sisterhood and their immediate families. Carmen’s new boy toy, Win (short for Winthrop), is particularly forgettable; although Brashares reveals a few juicy secrets from his past, she never breathes life into the character. By way of contrast, after three books, we know next to nothing about Bridget’s twin brother, Perry. And after Second Summer highlighted the renewed friendship between the girls’ mothers to spellbinding effect, it is frustrating to see the adults all but ignored in the follow-up.

True fans of the Sisterhood will not be surprised to learn about the girls’ college choices. Carmen will attend Williams, just like her father, Al. Bridget will go to Brown, a school that readily accepted her not for her scholastic aptitude but because she was an all-American in soccer. Lena’s headed to the Rhode Island School of Design to study art, and Tibby used her movie about Bailey from the last book to secure a spot in NYU’s filmmaking program. Naturally, they’re all anxious about beginning this new chapter in their lives, even though the schools are within four hours of each other (that was their one rule regarding college selection).

What a delicious opportunity for Brashares to explore the evolving nature of friendship! Ties between friends, of course, are not self-sustaining; pay too little attention to them and they sever. This tension haunts the book without ever being satisfyingly resolved. The Sisterhood contemplates what will happen to their friendships when they aren’t able to interact every day. What they don’t consider is that they will meet new girls to take each other’s places. What would happen if, for example, Bridget gets along smashingly with her future roommate, Aisha? I don’t really see the tightly knit circle of friends expanding to encompass a fifth, and maybe that could be a problem.

But instead of exploring these issues in enough depth, Brashares slathers on the subplots, with varying degrees of success. Tibby’s little sister, Katherine, Lena’s grandmother, Valia, and Carmen’s stepdad, David, all feature prominently in separate storylines, but do we really care about these people? And it doesn’t help that Brashares fails to develop the plot threads that are truly intriguing. Remember the budding relationship between Lena and Carmen’s stepbrother, Paul? Aborted. Remember the baby expected by Lena’s first love, Kostos, and his new wife in Greece? In Brashares’s words, it “failed to materialize.” (This may have been aborted, too, but for some reason Brashares steers clear of this controversial topic.)

And to that, I say, come on, Ann Brashares. Stop messing around. When rival Alice series by Phyllis Reynolds Naylor regularly explores topics such as molestation, masturbation and homosexuality with candor and honesty, you can at least raise the possibility that Mariana had an abortion. The fact that she comes from an extremely conservative family doesn’t let you off the hook. (A young girl that unprepared for motherhood would have considered it, if only momentarily.) Come to think of it, none of the Sisters has ever imbibed alcohol in the text (although Brashares has alluded to it), and the only characters who have ever smoked weed are Tibby’s parents. All the girls are still virgins, even if they have had some close calls. Look, I realize Brashares’s readership is relatively young—I’m not asking for I Am Charlotte Simmons here. But for four normal girls about to begin their freshman year in college, don’t these stats strike you as a little unrealistic?

So here’s my dream scenario for the next Sisterhood book. Bridget’s roommate, Aisha, turns out to be the roommate from hell, squeezing sympathy from her reticent father and uncaring brother, Perry. Tibby makes a new friend at NYU who acts just like Tibby and reminds her of Bailey and makes everybody else jealous. Carmen considers going all the way with Win and butts heads with her traditional, churchgoing mother because of it. Lena’s depression over Kostos turns to rage, most of which she channels into her art—but not all of it (because I really think those two ought to run into each other again). If Brashares sticks to this simple plan, she can make the Sisterhood relevant again. If she continues on the road she’s traveling, the Sisterhood books will become as insignificant as The Baby-sitters Club—enjoyable, to be sure, but nothing to which anyone would turn for an accurate portrayal of teenage girls.

That said, I teared up at the end of Girls in Pants. But maybe I’m just a big crybaby. I should probably save my tears for the Sisterhood movie adaptation, which will star Alexis Bledel (Gilmore Girls) as Lena, America Ferrera (Real Woman Have Curves) as Carmen, unknown Blake Lively as Bridget, and Amber Tamblyn, Joan of Arcadia herself, as Tibby. Ferrera aside, that sounds like kind of a dubious line-up. But not as dubious as some of the choices Brashares makes in her latest book.