Sildar Hallwinter offered the party a sum of gold to defeat the Redbrands and rescue, or bring back what's left of, his friend Iarno Albrek. Sildar believed Albrek to be a captive of the Redbrands, when in fact he had created the group and acted as their leader under the alias "Glasstaff."
After a confrontation with the gang in the streets of Phandalin, the party stormed their hideout in the ruined Tresendar Manor. They eliminated the remaining Redbrands, the bugbears sent by the Black Spider, and Albrek himself. During the raid on the Redbrands' hideout, they rescued Mirna Dendrar, Nars Dendrar, Nilsa Dendrar, and Carp Alderleaf, who had been taken captive to be sold into slavery.
Mirna is the wife of Thel Dendrar, who was murdered by the Redbrands for standing up to them. Nars and Nilsa are their two children.
Carp is the son of Qelline Alderleaf, a halfing farmer in Phandalin.