Lost Mine of Phandelver
Over five hundred years ago, a pact was made between a clan of gnomes and dwarves which became known as the Phandelver Pact. Together they mined the magically rich ores within Wave Echo Cave. Human spellcasters from nearby Phandalin joined forces with them and together they combined their collective skills to create a forge to craft magical items dubbed the Forge of Spells. Everything came to an abrupt end when orcs, craving magical treasures, sieged Phandalin and the Wave Echo Cave mine. The battle destroyed Phandalin and much of the mine as well, causing various cave-ins throughout. Very few survived the conflict to relate the tale. The Forge of Spells become legend and the entrance to Wave Echo Cave was lost.
Flash-forward to present day, the Rockseeker brothers, intent in finding and reopening this now-fabled mine, manage to locate the cave. Their activity was never a secret. A nefarious villain known as Nezznar the Black Spider, a drow wizard, has been watching and waiting for the dwarves to uncover this location. The drow desires to harness the Forge of Spells for his own purposes and has rallied bandit gangs and goblin tribes from within the region to aid him in this mission.