I decided before starting this one that I'd stick to five disciplines per adventure, rather than adding one each book. Partly because I won't necessarily finish every book without cheating, partly because it's more fun having to make hard decisions like that (or in book five, for example, your choice is limited to which discipline you don't want (probably Mindshield or Hunting)). I will, however, carry items over from adventure to adventure.
It's a good job I made that last decision, because I don't think I'd have managed this one without the Sommerswerd. More on this later.
Caverns of Kalte is easily the weakest book in the series so far. It lacks any real plot, and feels far more like a random dungeon-crawl than Flight from the Dark. It also has a number of significant new problems.
Firstly, it's far less fair on the reader as regards death than the previous two. Not, I should add, because it frequently punishes you directly for making a good decision, but because it contains several points where your survival is down to a random number generation. I died to one of them my first time around.
It also adds a new mechanic, wherebye disciplines give you bonuses to random rolls rather than helping you explicitly. I'm not very keen on this, at least not to the extent that it was rather overused in this book. If I have Tracking, I damn well want to be able to Track stuff, not just be slightly more likely not to die instantly than if I didn't have it.
To take one explicit example of random death, the entry to the ice fortress about half-way through the book requires you to have a key of sorts. There are three ways (so far as I could see scanning through) of obtaining this key; two of them involve winning very difficult fights that even the most combat-capable character (i.e. 19 CS + 2 WS +2 MB +8 SS) stands only a 40% chance of winning. The other involves randomly stumbling across the one instance of the key that isn't heavily guarded, something which does not simply require you to be diligent in exploring, but also to make several decisions at various points that have nothing to explicitly recommend them over the alternatives.
It's also the second book to use a fake time limit. That is, the text tells you have only thirty days, or something to complete your mission, but since it's impossible to actually go over due to the magical staff of teleporting you conveniently get access to, the gameplay doesn't actually support the plot. This makes the decison near the beginning of the book, where you have to choose between a "slow but easy" route and a "fast but difficult" totally unfair and not at all as presented, especially since the difficult route is actually easier.
I'm being rather harsh here, so I'll temper the discussion with some faint praise. The first section of the book, where you navigate the harsh, icy, and freezing kalte (errrr.... pun intended, but I'll shut up now) wastes in which the titular caverns are located, feels tense and exciting. The writer manages to create the atmosphere of sturggling to survive in a harsh environment rather well. Unfortunately, he fills this section with random dice rolls to determine what happens next, meaning you actually get to make rather few choices.
The later sections of the book, while they contain fewer random rolls, instead opt for having you wander randomly around a relatively featureless dungeon, sorry fortress, with little if anything to base your decisions to turn right or left on.
I seem to be using the word "random" rather a lot, and if had to summarise Caverns of Kalte, that would certainly be how I'd do it.
I should emphasise that I did still enjoy reading it; Joe Dever writes as well as always, and it's well-worth playing, just not as good as the preceeding books.
The climax is actually not bad, where you actually arrest the traitor wizard you've been pursuing. His punishment is also suitably epic and cool.
One final harsh word. Or two.
I really don't know how I would have completed the book without the Sommerswerd (the infinity-plus-one sword from book two). The combats were generally relatively easy (except the final one, which was very close) with my +8 bonus, but without it I'd have died quickly. Inevitably, if you hand out +8 combat bonuses, you'll find it impossible to balance the fights for those with and without the bonus.
Note that I suspect it's possible to beat the game without the sword, but I'm pretty sure this requires you to find the optimal path, which since everything is totally random, will take a long time. With the sword, so long as you avoid the key problem (see above), you stand a very reasonable chance. I really think Joe Dever would have done better to simply give every player of the book the Sommerswerd if he wanted it to be as powerful as it is, regardless of whether they'd played book 2. He could then have balanced the fights properly for the sword and not worried about people without it.
I re-iterate that Healing is very good. Though Dever has begun to put in a few more opportunities to heal even if you don't have the discipline, but I don't believe there're enough, really.
Oh, and the displines I chose for this run (I completed the book on the second try, stumbling across the key in the right place):
Camoflage, Tracking, Healing, Animal Kinship, Sixth Sense