Allegiant is a brave conclusion to Veronica Roth's best-selling Divergent trilogy. While I felt Allegiant was the weakest of the series in terms of plot and pace, I was impressed that Roth allowed her characters to be true to themselves, even though that meant denying her readers the satisfaction of a happily ever after. 
 I didn't find Allegiant as entertaining as the previous two installments in the Divergent series. I've tried to find solid reasons why. 
 [BEWARE! HERE BE SPOILERS] As soon as the suspicious writer in me saw that Roth had decided to alternate the point of view in this book between Tris (who previously had been our only first-person narrator) and Tobias, I thought, "Oh dear. One of them isn't going to make it". And, in this sense, Roth makes good use of Tobias, giving us more access to his character so we feel closer to him should he have to be the one to hold our hand and lead us gently to the end of the story. 
 But then this shifting point of view means taking half the story away from Tris, the character we have come to identify with so much throughout the other two books. Those books are her story, but Allegiant is only partly hers. Perhaps this is one reason why I could have abandoned Allegiant two thirds through and wouldn't have been bothered knowing how it all ended. I think another reason is linked to the setting of this book. For me, moving the action outside the confines of the city led to a staggering drop in tension. I didn't feel the characters faced the same level of peril and, consequently, all the violence/action felt forced, as if our heroes were desperate to make trouble just to give themselves something to do. 
 I'll be interested to see whether the film adaptation of Allegiant has the courage to use Roth's ending. 
 Overall: unfortunately I felt the series went out with a whimper rather than a bang. However, Roth has to be given credit for sticking to her guns and letting her characters act in a way that is consistent with everything we've seen of them previously in the series. Even if that meant breaking some of her readers' hearts.