One of my favorite modules ever, if not THE favorite
The Expedition to the Barrier Peaks was, essentially, the catalyst for my entire D&D campaign universe.
I intended to run a campaign of AD&D with a bunch of players who had all been playing for a few years but never together. We met at camp and had campaigns running with our non-summer/school time chums. Each wanted to use the character they had already been playing but I insisted that if they did, the PCs in my campaign belonged to my campaign. They were basically alternate, parallel world versions of the guys they'd been playing. They all said yes and we were off!
I altered the background and story slightly...a Mind Flyer, fleeing from knights and brave peasants from a near by village fled into the mountains only to discover a secret passage into the Barrier Peaks vessel which had been buried after crashing hundreds of years before. Most of the crew was dead and gone but the ship's commander survived in a suspended animation chamber. Curious to learn more of this bizarre, hidden 'castle' the Mind Flyer released the commander and sucked his brain dry. The result was utter maddness and the Mind Flyer's personalty and goals merged with those of the ship's captain. Soon, he commanded armies of Metal Men (Robots) to capture nearby villagers for sustenance and psionic research.
Enter, the Neutral Man, an almost elemental entity from the plane of true neutrality, the Concordant Opposition. Foreseeing the activities of the Mind Flyer, now calling himself Lord D'Ark, as a threat to all beings of all alignments on this world, the Neutral Man summoned a force to defeat the mad creature before he destroyed the world (exactly how or why he was going to destroy the world eludes me at present - this was written by my 12 year old mind and I'm 39 now). The heroes chosen came from all walks of life and all alignments, banded together by this Watcher-like fellow to save the day. It was an awesome adventure! Good guys and bad guys worked together, refused to work together, turned on each other and even changed alignment. In the end, the world was saved, D'Ark believed dead, the villains were given pardon and the heroes remained together to form a sort of medieval Justice League. The team used the Barrier Peaks as its base/HQ, later merging magic with some of the SF tech because they simply assumed the place ran on some strange sort of wizardry. Each of the members of the party had communicator type devices that they found in the ship/'castle' and they also kept many other gadgets and gear.
Many, many years later, when I started gaming with a very special friend of mine, I set my new campaign in the same world some 25-30 years of game time later.
I ran the original version, less modified, at least two other times for two other groups. I'll never forget how one group got inside the back flap thing on the Bullette and road around in it for a bit. I met Tony DiTerlizzi at Gen Con once and told him that story because he was looking through a copy of the module. When I met him again a year or so later he said, "I remember you. You're the guy with the Hatchback Bulltette."
Good times, good times.
AD
Brandon Wheeger: "But I want you to know that I'm not a complete brain case, okay? I understand completely that it's just a TV show. I know there's no beryllium sphere...no digital conveyor, no ship... "
Jason Nesmith: "Stop for a second, stop. It's all real."
Brandon Wheeger: "Oh my God, I knew it. I knew it! I knew it!"