You'll meet Cernd during the Animal Troubles quest in Trademeet. He'll be in jail for his own protection, but with his help (or not) you'll stop the shadow druid Faldorn from sending animals to attack the town. See the Trademeet page for more information about the quest.

After completing Animal Troubles, when you next visit Athkatla, Cernd will spot his former neighbor, a man named Igarol. Cernd will be happy about the reunion, but Igarol won't be, and he'll accuse Cernd of abandoning his wife Galia while she was pregnant. Igarol will then demand that Cernd go to his former home to see what became of her.

You'll find Cernd's former home in Waukeen's Promenade, near the Adventurer's Mart. Inside, you'll find the place abandoned, with only the vagabond Catis squatting there. When Cernd asks Catis where Galia is, Catis will direct him to the home of his former serving girl, Fennecia, who is now a nanny.

You'll find Fennecia's home nearby but a couple of levels higher up. Inside, Fennecia will have the same reaction to Cernd as Igarol, and she'll refuse to say anything while he's around. After sending Cernd outside, Fennecia will get more talkative. She'll reveal that Galia hooked up with a nobleman named Deril after Cernd's departure, and that Deril treated her poorly. Worse, you'll learn that Galia died under suspicious circumstances soon after giving birth, and that her infant son is still with Deril.

You'll find Deril inside his estate in the southern part of the Government District. He won't take kindly to being interrupted during a dinner party, and he'll encourage Cernd to leave. But Cernd won't be deterred, and the encounter will go one of three ways:
  • If you tell Cernd to threaten Deril, then Deril will hand over Cernd's Baby, and he and his guest Lagole Gon (a lich) will dimension door away. Before leaving, Deril will tell Cernd, "This is not over! I will deal with you later!" but you'll never see him again.

  • If you tell Cernd to accuse Deril of murder, or to attack Deril, then Deril will attack you, and his guest Lagole Gon (a lich) will watch. With six against one, the battle against Deril should not be difficult, and you'll earn 26,000 xp for defeating him. After the battle, Gon will hand over Cernd's Baby, and then he'll dimension door away.

  • If you tell Cernd to "give it a rest," then he'll leave your party and attack Deril on his own. Deril will defeat him easily and then dimension door away.
Note: If you can kill Lagole Gon before he leaves, then you'll earn 26,000 xp for him, too.

Regardless, as long as Cernd survives, he'll end up with his son, whom he'll name Ahsdale, and he'll leave your party and take him to the Druid Grove. This will earn Cernd 50,000 xp and the rest of your party 20,000 xp. Later, when you visit Cernd in the grove, he'll be available as a companion again.