The Hole in the Oak is a classic dungeon adventure in digital PDF format for 1st–2nd level characters (Old-School Essentials). Adventurers follow a babbling brook that leads them into shimmering grottos, a ruined temple, and the lair of a crystal-eating dream dragon.

The PDF contains 57 keyed areas, a rumor table, a treasure overview, and rich dungeon background. Written by Gavin Norman, with illustrations by Nate Treme that add a fairy-tale atmosphere.