Who told them the Kai Lords would all be celebrating at their monastery (as they have on that day for hundreds of years)? Vonotar the Traitor!
Who told the Darklords that their unprecedented airmobile attack would take Sommerland by surprise? Vonotar the Traitor!
Who told the Darklords of the ancient and famous alliance between Sommerland and Durenor and that an envoy would be sent to summon the Durenese? Vonotar the Traitor!
Who tried, but failed, to stop the Durenese fleet? Vonotar the Traitor!
Who annoyed Banedon the Wizard who is apparently making a name for himself amongst the Brotherhood of the Crystal Star, but has only had cameo appearances so far? Vonotar the Traitor!
Vonotar has overthrown Brumalmarc, the leader of the Ice Barbarians. Obviously this cannot be allowed to stan, so you - Lone Wolf - head to Kalte to
Lone Wolf sails north and has to cross the frozen wastes to the Ice Fortress of Ikaya. The usual hazards of arctic travel - bad weather, dangerous ice, equipment failing - occur, along with the more exotic threat of the Ice Barbarians who turn up on skis with child-archers on their backs. Getting away from them, you inevitably end up in the eponymous caverns, and wander through the various paths there. The Sommersword comes in hand facing an undead being called Akraa'Neonar, and after you rescue a wizard called Loi-Kynar, Vonotar is beaten and you're teleported back to your ship. Vonotar is thrown through the Shadow Gate to the plane of Daziarn from where no one ever returns. No one. Ever. (See Book 11 The Prisoners of Time and World of Lone Wolf Book 3 Beyond the Nightmare Gate)
Kalte is quite well written - the weirdness of the fortress, which was created by the ancients to imprison the Ice Demons was good, and the obligatory furry serpents had a twist. Overall a good first journey out of the Lastlands.