Mother's Heart is the fourth main quest in Horizon Zero Dawn. Aloy gains access to the Nora capital of Mother's Heart for the first time. Inside, she will take part in an annual festival before the start of the Proving.
Aloy meets Rost outside the gates of Mother's Heart. He tells her to meet High Matriarch Teersa who will lead her through an annual festival before the start of the Proving. Before she enters the city, Rost tells her that he will not see her again. She pleads with him to reconsider his words, but Rost assures her that her acceptance into the tribe will lead to the answers she seeks. The front gate guards of Mother's Heart attempt to turn her away before Teersa intervenes.
The city is bustling due to the arrival of envoys from the Sundom, who have visited the Nora lands for the first time in several years. Teersa also tells Aloy that an "old friend" is waiting for her. Turns out, it is Teb, the young Nora brave she saved during the events of Lessons of the Wild. Teb is now a Stitcher and gives her the Nora Brave armor as a long overdue thanks. Karst can also be found in Mother's Heart and wishes Aloy the best of luck in the Proving.
As Aloy continues enjoying the festivities, she notices the foreign envoys are being given a rough reception by the Nora crowd due to the bloody history between the tribes. Erend, an Oseram, calms them when he explains that the Carja Sun-Priest Irid is attempting to apologize for the capturing, killing, and slavery that occurred under the former Sun-King, Jiran. Aloy spots a strange man named Olin wearing a Focus in the crowd. She briefly chats with him before being introduced to Erend.
Afterward, Aloy takes part in a prayer lantern ceremony that officially starts the events of the Proving. Night falls and Aloy finds the lodge, where she meets Resh, a guard who makes his distaste for her perfectly clear. While preparing for bed, Aloy butts heads with Bast and meets Vala, another Nora who wishes to win the Proving.
- Talk to Rost. He'll be waiting for you near Mother's Heart.
- Enter Mother’s Heart
- Talk to Your “Old Friend.” Teersa said someone is waiting to see you.
- Go to the Matriarch’s Lodge
- Scan with your Focus to see what it detected
- Talk to the Man Wearing a Focus
- Go to the Blessing Ceremony
- Talk to Teersa
- Talk to Olin (Optional)
- Enter the Hunters' Lodge where the aspirants will sleep the night before the Proving.
- Confront Bast
- Talk to Vala (Optional)
- Go to Bed and try to get some sleep.