Recently I have read chapter 21 of Divergent. Tris got first ranking for stage two of initiation and before, the last person who got first ranking in stage one, got attacked. Sure enough Tris got attacked by three people, Al, Peter and Drew. Luckily Tris got saved by Four.
I think it's strange that Al would attack Tris. Before in the book Al told Tris he liked her. He seemed kindhearted, like he would never hurt anybody.