As you travel north east on Old Tristram Road, Leah tells you that Adria was her mother. She does not know much about her. She died when Leah was very young. Leah was raised by Uncle Deckard. You ask Leah if she knew her father. Leah tells you that she was told he was a great warrior who was lost when Tristram fell to the demons.
Your conversation does not last long, for soon you are attacked by risen and undead along the road. Fight your way through them as you keep heading northeast. You can also stop and talk to Leah. If you ask her about Tristram, she says that for a long time, Uncle Deckard avoided coming back to this place. There were a lot of ghosts here for him. This is where Diablo drove old King Leoric mad and terrorized the people. Leah does not know what really happened here, but whatever it was, it was horrible. Nearly everyone who survived went mad.
If you ask Leah about Adria's death, she tells you that details are hazy, but she knows that Adria was obsessed with chasing the arcane. She knew she could never raise a child. Uncle Deckard believes that the madness and horror of her life finally caught up with her.
The road soon turns southeast, and you cross a small bridge and arrive Adria's Hut. Your objective now is to search Adria's Hut. As you search it, you uncover a hidden cellar door. You get a new objective, to enter the Hidden Cellar in Adria's Hut.
You sense the cellar has great power within. Leah tells you how people thought her mother was a witch. Suddenly Leah notices Captain Daltyn - Former Captain of the Guard. He is a boss monster (Purple) and your task now is to kill Captain Daltyn and the Risen. This can be a challenging fight. Be sure to have a health potion ready, and to touch any red health globes that spawn as they become available. If you die, you will get a message saying "You have died". You will be revived at the nearest checkpoint when this happens. There is no other death penalty for being killed until level 10, but after level 10 your armor and items will take damage with each death. If you are killed, press the "Revive at last checkpoint" button. In this case, the checkpoint is just outside Adria's Hut, and as soon as you respawn go back to the Hidden Cellar beneath the Hut immediately and keep fighting Captain Daltyn.
When you defeat Daltyn, he will most likely drop a magic item. Pick up any loot. Leah is no longer following you. Your objective now in the Legacy of Cain quest is to talk to Leah in the Hidden Cellar.