I think this is probably the best-written book of the whole series. The first two chapters are a thing of (harrowing) beauty - it shows this was KAA's comeback to zero-to-published writing in the series after stepping away on #27. 
 But it has an ending problem. Which I've found is recurring - 41 had an ending problem too, as do most of the Ellimist books, which is the inevitable problem in having a walking Deus-ex-Machina in the cast.