We've encountered a shift in the novel at this section, just like initiation has shifted from stage one to stage two. Before, Tris was merely another contender in this vicious competition, and a mediocre one at best. She was learning the ropes, making friends, and developing a new identity just like everyone else. Now, though, the mood has become darker and more ominous as Tris begins to delve deeper into herself. The simulations are increasingly more violent and terrifying. And, of course, Tris's Divergence is coming more and more into play. For the first time, we get a concrete explanation as to why it's so dangerous to be Divergent: because the Dauntless leaders, scared of something the Divergents are capable of, have been discreetly killing them off. There is certainly a different feel to this section of the novel, and Tris has much bigger concerns than just her rank. The stakes are getting higher.
And on an even larger scale, the schism between Abnegation and Dauntless is threatening to destroy the fragile peace between the factions; Erudite are clearly belligerent, judging by the things they've been printing, and their direct attacks against the Abnegation government are impossible to ignore. Will Tris get dragged into this to defend her family's honor and her birth faction? What about her brother, Caleb, who is now an Erudite? She has enough to worry about, what with initiation and death threats for being Divergent, but this problem will undoubtedly find her in some way. For now, knowing only what Tris knows, we must question Erudite's motives behind the rumors and false information they're spreading.
Tris's success in stage two of initiation shows that what she may lack in Dauntless fighting capabilities and strength, she makes up for in her mental response to fear. Whether this is innate or merely a product of her Divergence is uncertain, but either way, her first place ranking makes her a threat. That Tris's success and strength make her friends feel weak is, of course, not a good sign, but this undoubtedly stems from the demanding and intense competition facing the young initiates. They all came here with the intention of making it through initiation, so when someone threatens that, even if it's a friend, fear and anger are logical responses. But while Will and Christina simply take some time to cool down, Al takes his anger to a whole new level, going so far as to possibly kill one of his best friends in the faction.
Al's choice to betray Tris and join up with Peter and Drew, initiates far stronger than him, shows his mental and emotional inability to handle the pressure that Dauntless throws at him. Did he truly think he had something to gain from this, or that teaming up with Peter and Drew wouldn't turn out to be a huge mistake? They were using him, no doubt, and it's interesting to try and delve into Al's mind and determine what prompted this decision. It may have been a fit of insanity or a cold, calculated choice, but either way, it's pretty clear that at no point did he foresee the terrible consequences of his actions.