Really big trouble is an understatement these days. The war between the Yeerks and the Animorphs is full on - and it's definitely going to get worse. But Cassie, the other Animorphs, and Ax have a lot more going on than just trying to stay alive. Now they've got to actively protect their families and the free Hork-Bajir. And they no longer believe they can do it alone. The Yeerks are just too powerful. So Cassie and the others have to ask themselves a very important question: Is it time to increase their numbers? They all remember too well what happened with David - the Animorph gone bad. But this time do they really have a choice?