The Sunken Temple of Chloren-Var is a long form adventure that has everything needed to jump in and run a game. There's enough material to pick and choose sections of the adventure and the temple rooms can be changed to raise or or lower the difficulty on the fly.

I really appreciated the amount of lore and back story as I haven't had much experience on the DM side of things. For $6 it's worth buying as a stand alone adventure or to incorporate parts of it into your own.