Seen as everyone here always has the best ideas I thought I might ask for a little advice.
I am currently DM'ing a party of 5 and we're reaching the end of book 2 with the implementation of Dudemeisters Monster Kingdom (kudo's for the write on that one, it's a blast). Our last session was yesterday and in it the party finally raided Hargulkas stronghold for some well deserved revenge. To begin with all was going well, that is until they decided to split the party a bit and ended up getting Nagrundi, Kargadd and two regular trolls into the fray at the same time. This proved a bit too much for them and they were forced to retreat. A parting fireball from a very angry Hargulka put the party on -3, 1, 1, 9 and 8 hitpoints, making retreat the only real option >:).
Now comes my question. Hargulka, Kargadd and one ordinary troll are remaining (although an extra could be added seen as they havn't explored the entire complex yet), they are sealed in by an army and the party plans on assaulting the fort again in 1 or 2 days depending on how much healing they can muster in the meantime. Hargulka obviously expects this and will be preparing accordingly. What can they do to make they assault more difficult, and mainly more interesting, for the PC's? I'm against them running in again and just running the encounters as written because it seems illogical to me. I'm also not sure about letting Hargulka escape some way because the party is really riled up and they deserve the satisfaction of setting ablaze the troll who almost destroyed their kingdom. Short of barricades and maybe a rudimentary trap I can't come up with much as the trolls lack the resources, space and intelligence to think up much else.
Any ideas to spice it up a little would be welcome :)