Training with the Enchantsmith

Training with the Enchantsmith is the fifth main quest of the campaign, and it is one of the most important: it teaches you the enchanting system. Across 23 objectives you hunt down three enchantment books — the Book of Healing Smite, the Book of Piercing, and the Book of Ancient Alchemy — searching the woods, entering a wishing well, investigating an empty lectern, and fighting off illager ambushes along the way. You hand the books to the Enchantsmith, return to Brave Haven, find their stall, then clear a dungeon to recover the Book of Ancient Alchemy from a pedestal, survive the ambush that follows, and report back.
Rewards
First completion rewards the three enchantment books themselves: Piercing, Healing Smite and Ancient Alchemy, which unlock those enchantments in your library — see Minecraft Dungeons II Enchanting Guide for how the system works from here. There is no boss encounter. You must finish The Silence in Little Howl before it becomes available, and completing it unlocks Corruption in the Woods — Minecraft Dungeons II Quest Guide and Part of the Pack.
Known issue
At launch, the quest marker could point at a stone door that never opens. If that happens, fast-travel back to Brave Haven, walk out through the front gate and take the first door on the left along the path — entering it updates the quest correctly.
