I sat there, staring, as my players laughed hysterically.

In Krynn, our campaign setting of choice, there lay a smoldering, melted mesh of wizard and draconian, all that remained of my intricate, detailed, meticulously planned plot.

This was our 2nd session of the campaign, and at this point the party was level 4 and consisted of a focused conjuror specialist wizard, a human swordsage, a tarmak mystic (DMPC, so he didn't do much), and a cleric. The wizard was fairly optimized and the cleric geared towards combat (but not optimized). I guess my problems started there. Two tier 1 characters, a tier 2, and a tier 3.

In any case, the first part of the adventure went flawlessly, and left me feeling very content as a DM. The PCs recovered two magical artifacts from angry draconians, battled and were appropriately challenged by an animated twelve headed statue of Takhisis the Dark Queen after which point the entered into a duel with an elven noble (who was actually a level 8 black robed wizard...) named Alfelias.

Ah, Alfelias. Perhaps one of my favorite villains I've ever designed, outside of my satisfyingly evil Scar (a mul warblade, but that's besides the point ). What plans I had for Alfelias. The PCs handed over the magical music box they'd found to him after he pretended to be defeated, and I reveled in my brilliance.

My brilliance began to plummet as the PCs followed Alfelias to his evil lair about ten levels early. I tried at first to deter them with evil draconian assassins, but then decided that as soon as they arrived and encountered Alfelias' shapeshifting sivak CR 6 guards they would abandon him and try for a different course of action. My brilliance, at this point, had tapered out.

When the PCs confronted and soundly butchered all of the CR 6 guards to Alfelias' underground hideout, I felt the first hints that maybe something had gone wrong. They proceeded to completely smash through my dizzying array of traps and guards before catching my CR 9 aurak draconian villain Drachma and Alfelias (CR 8) and killing them both in the surprise round. My plot was crushed. My brilliance...nonexistent.

So have any other DMs had similar experiences? And sorry for the wall of text in which little was actually said...