A Hatch Opens!

From the introduction: An 8-hour adventure for 7th-9th level characters This adventure puts the PCs at a disadvantage against a horde of goblins in a wizard’s tower. Through trial and error, the goblins have gained mastery over the tower and all its traps and defenses. By the end of the adventure the PCs will have developed a grudging respect for creatures they thought they’d outgrown, and a nervous tic in response to the phrase “A Hatch Opens!”