Hazel Grace Lancaster starts her story by telling us that her mother thinks she's depressed. Hazel doesn't deny that she's a little fixated on death. She considers just about everything, including her cancer, a side effect of dying. Her mother and doctor agreed she should attend a weekly cancer support group. The leader of the support group is a cancer survivor named Patrick who constantly talks about the fact that they meet in the heart of Jesus since the group meets in the basement of a cross-shaped church, directly at the spot where Jesus’ heart would be. Despite his surviving cancer, Hazel views his life as dreary. In the meeting, Hazel introduces herself. She is sixteen and originally had thyroid cancer, though it's spread to her lungs, too. Hazel equates the sharing part of group to a circle jerk of support where everyone talks about how they're winning the fight. The only part of support group she likes is a guy named Isaac who lost an eye to cancer and may lose his remaining eye as well. They both sigh derisively at people's stories.
After a few weeks, Hazel attends a meeting where she's surprised by the presence of a new and beautiful boy who stares directly at her. His name is Augustus Waters, and he's attending the meeting to support Isaac, who discovered he will soon lose his second eye to cancer. Augustus is a survivor of osterosarcoma, and when asked what he fears, he says “oblivion.” Hazel, who rarely speaks, says to the group that eventually everyone will be dead, and everything humanity has built will have been for naught. In her narration she explains she learned this from her favorite novel, An Imperial Affliction by Peter Van Houten. When the meeting wraps up Isaac introduces Augustus and Hazel. Augustus says Hazel reminds him of Natalie Portman in “V for Vendetta.” The two flirt, mock the meeting's location in the “literal” heart of Jesus, and watch Isaac make out with his girlfriend, Monica. Placing a cigarette between his lips, Augustus invites Hazel to his place, to watch “V For Vendetta.” Hazel is disgusted by the cigarette but reconsiders when Augustus explains that he never lights it. Rather, he enjoys the metaphorical resonance of putting something that kills between his teeth and denying it the power to kill him.
Functionally speaking, the first few chapters of the novel are dense with a variety of introductions pertaining to characters, background, setting, and tone. First and foremost, we meet Hazel Grace Lancaster, the novel’s chief protagonist and narrator, and become acquainted with the skeptical way she views the world. Cancer has rendered Hazel perhaps more jaded and philosophical than her non-cancer ridden peers. Already on the first page of the narrative Hazel let’s on about her theory of side effects, namely that almost everything conceivable can be viewed as a side effect of dying. She also attacks the convention of portraying kids with cancer as heroic victims, making no qualms about the fact that she sees these conventions as empty cliches. Right away this information tells us that Hazel isn't an unrealistic romantic, and that of all things, she perhaps appreciates honesty most. She suggests that honesty is precisely the reason she loves An Imperial Affliction, the book she considers her personal bible. The author, she says, is the only person who understands what it's really like to be dying, which implies that the book is the only one she's found that accurately portrays that experience.
Hazel's jadedness forms the basis for her friendships in this chapter. She and Isaac communicate through their groans at the sentimentality and unrelenting optimism of the support group. It also creates an attraction right away between Hazel and Augustus. Physical appearance aside, it's Augustus's saying that he fears oblivion and then Hazel following with her speech on the inevitable demise of humanity that creates the first bond between them. They follow that by mocking the notion of the support group being in the “literal” heart of Jesus. The three share a distaste for what they evidently view as the intellectual and emotional dishonesty of the support group, and that mutual feeling allows them all to bond.
One of the pervasively recurrent themes throughout the novel is the underlying current of existentialism, and many of the basic tenets of existentialism are already prevalent by the conclusion of the first chapter. Concerns about authenticity, uncertainty, fear, meaning, and death—to name just the most prominent of existentialism's themes—are practically ubiquitous. The most notable example is Hazel's speech to the group about the guaranteed end of humanity. Given the cast of characters, the prevalence of existential themes is no surprise. By their very nature, Hazel, Augustus, Isaac, and all of the cancer kids at the support group are compelled one way or another to deal with the inevitability of dying in a way that other people in their age group, and even their parents' age groups, don't. Death isn't an abstraction, as Hazel's experience at the support group makes clear. The meeting ends with Patrick reading off a list of names of former members who have died, and Hazel imagines her own name at the end of that list, showing that she's completely aware that her own death is inevitable and probably imminent. Through these details it's obvious that imagining death and trying to find meaning in the world aren't just intellectual exercises for Hazel and the others but very real concerns in their everyday lives.
The first chapter introduces some other important elements as well: Augustus's cigarette, which is major symbol in the novel, and the motif of metaphors generally. Augustus tells Hazel he keeps the unlit cigarette in his mouth for its symbolism, or “metaphorical resonance” as Hazel phrases it. It's a way of feeling he has control over the thing that has the power to kill him. In this case, that thing is cancer, represented by the cigarette, a well-known carcinogen. These sorts of metaphors turn up throughout the novel, with Augustus's cigarettes probably being the most prominent of them. Generally speaking, metaphors allow the characters to deal with emotionally fraught topics, like death and the emotional devastation their deaths will ultimately have on the people around them, without them having to always name those things directly. They become a shorthand, and in certain instances the metaphors give the characters a little emotional distance from these topics. In Augustus's case, he can put the cigarette in his mouth to regain a sense of control rather than having to stop and think through his cancer with all the emotional baggage that involves.