Not going to lie, Rachel is my favorite. For more than one reason its fitting that it be from her perspective that the 'David' trilogy ends.
Tobias is not the only member of the Animorphs to have been changed forever by the war with the Yeerks. They all have been scarred and have grown in response to the pressures they face. This book deals with Rachel and Jake facing their own personal doubts and fears and admitting to each other how much they have changed.
There are some surprises in store, as well. In my opinion, it makes up for the previous cliffhangers, plot-drops, and any other issues. The Visser has some aces up his sleeve, David takes things up a notch, and things get personal.
And things get really dark.
Next: 'The Hork-Bajir Chronicles'
Previous: 'The Threat'