"Depression is not a side effect of cancer, it's a side effect of dying." Hazel Grace Lancaster (Shailene Woodley) has been through a lot in her 17 years—she was diagnosed with thyroid cancer at the age of 13, a disease that has recently spread to her lungs—and it is her terminal prognosis that has given her a wizened outlook on life and mortality. She realizes she is going to die, but so is everyone else, eventually. The difference is that she has even less time than most, and knows that she will probably never grow into an adult. A reverent but never stodgy adaptation of John Green's best-selling 2012 novel, "The Fault in Our Stars" sounds on paper like a major downer, but the story comes at its morose subject matter from a place of insight and affirmation. It's sad without wading into mawkish melodrama, and cheekily humored without becoming inappropriate or tacky.

At the film's center is Shailene Woodley (2014's "Divergent"), whose range of emotional honesty as an actor continues to astonish with each new role. Urged to attend a weekly cancer support group, her Hazel Grace reluctantly agrees as a way of appeasing her tirelessly supportive mother, Frannie (Laura Dern). It is here that she meets Augustus Waters (Ansel Elgort), an Osteosarcoma survivor, currently cancer-free, whose lost leg is a daily reminder of the sacrifice he made to live another day. She is hesitant to get too close, knowing that a serious relationship will only end in heartbreak, but there is no denying the bond they share and all of the little things they have in common. Soon after Hazel Grace turns Augustus onto her favorite novel by author Peter Van Houten (Willem Dafoe), one that speaks to exactly what she is going through, they are surprised and excited when they start an email correspondence with the famed writer. When he invites her for a visit to his home in Amsterdam, it is a once-in-a-lifetime opportunity she feels as if she cannot pass up. A trip to the doctor, however, comes with the crushing news that she may be too ill to safely travel.

"The Fault in Our Stars" was directed by Josh Boone (2013's lovely, underrated "Stuck in Love") and penned for the screen by Scott Neustadter and Michael H. Weber (2013's "The Spectacular Now"), and the results overflow with their collective love for the material. This is far from the type of sudsy teenybopper romance certain viewers might be expecting, the script embracing the joys and pangs of reality while detailing a love story that is no less meaningful for being so fleeting. The conversations Hazel Grace and Gus share are not shallow traded sweet nothings, but traverse everything from books, art and culture—they patronize Joep Van Lieshout's "Funky Bones" sculpture on the grounds of the Indianapolis Museum of Art—to debates about the existence of God and the afterlife. The latter topic is something that average teenagers probably wouldn't be as quick to openly discuss, but it weighs more heavily over two people who have stared, or are continuing to stare, death in the face.

Shailene Woodley and Ansel Elgort (2013's "Carrie") are a lovely match, impeccably cast as romantic leads mere months after they played siblings in "Divergent." This outside knowledge could have turned things uncomfortable or even creepy, but the memory of them in that dystopian sci-fi drama vanishes the second they embody these enormously different characters. There is nary an ounce of artifice in what Woodley and Elgort have accomplished as Hazel Grace and Augustus, her initial hesitancy to get close to him broken down by his positive, "live-for-today" mentality. A scene where a eulogy is presented about someone who is still alive to witness it is at once uplifting and devastating, the performers dexterously handling the challenge of striking a note both truthful and free of manipulation.

As mother Frannie, Laura Dern (2012's "The Master") is astoundingly generous in the way she interacts with her co-stars while building a heart and soul for this woman who must somehow prepare to move on once her only child has passed away. With the exception of her brilliant turn on HBO's prematurely canceled "Enlightened," this is Dern's meatiest role since her last David Lynch collaboration, 2006's "Inland Empire." Willem Dafoe (2014's "The Grand Budapest Hotel") is riveting as author Peter Van Houten, the details of his meeting with Hazel Grace and Gus best left unrevealed for those who have not read the source material. Suffice it to say, it is an unforgettable scene—tough, uncompromising, and accurate to the way reality rarely matches expectations—and is followed by a beautifully realized set-piece at the Anne Frank House that is just as memorable. Finally, Nat Wolff (2012's "Peace, Love & Misunderstanding") is likable as Gus's best friend, Isaac, a lovelorn guy about to lose his second eye to cancer, but he also gets the one annoyingly cloying moment in the film, a piece of would-be physical comedy involving basketball trophies that rings resoundingly false. The failure isn't in Wolff's performance, but in director Josh Boone's decision to leave it in the finished edit at all.

"The Fault in Our Stars" is dignified and genuinely moving, a winsomely three-dimensional romance set against an unavoidably fatalistic backdrop. There is a revelation of sorts near the end of the second act, one that can be easily guessed, but do not expect a last-minute remission for Hazel Grace or anything of that sort. The film follows its female protagonist to a natural conclusion that has nothing to do with death and everything to do with the experiences she's had and the peace she makes with herself, and the loved ones around her. For Hazel Grace Lancaster and Augustus Waters, theirs is a whirlwind love of the kind that doesn't come around often, and that some, ultimately, never find. There isn't enough time for them to say and do all that they want, but then, is there ever?