SPOILERS AHEAD!
I recently replayed Search and Rescue in Eveningstar and was stuck with how odd the adventure was.
On the surface, and right up front, it is a mission to rescue some lost adventurers. However, a small crack in a wall in a side passage of this quest leads to an optional and completely separate Underdark adventure. There is seriously enough material and mapping that there are two medium length adventures in this single quest title. The first of course is the mission to an old tomb to rescue adventurers that eventually leads to a showdown with a Red Dragon. A wholly viable and self-contained story. The second (optional) quest involves infiltrating and stopping a Drow stronghold from bringing Slaad warriors to our world. Again, completely self-contained with plenty of mapping and content to make it its own quest.
Most optionals are simply side tasks with a very simple completion criteria - kill a mini-boss, find a few lore objects, etc. This optional however is truly an entire quest on its own.
I'm curious as to the reason behind this. As I said up front, it makes this adventure every odd. It's almost like they created two quests and then said, 'You know what? We don't really have a reason to start a Drow quest on its own. Let's just jam it into that dragon quest with the tomb."
Anyone know why this quest is set up this way? It seems like such a waste of a lot of really good content to be thrown away as simply an 'optional' that many will never play.