You have just exited the Weeping Cairns and what you witnessed inside was a sign that Lilith had already passed and had gotten to Airidah.
With a hint that Airidah and Lilith may be working together, you and Yorin will need to proceed cautiously into the Ancestor Heights.
There is a nearby village that may have survivors, it looks like you and Yorin will need to find out if anyone was left alive after Lilith came by.
How To Get Harrowed Lament Quest?
Harrowed Lament begins immediately after you have exited the Weeping Cairns during the completion of the Exhuming the Forgotten quest.
Harrowed Lament Quest Objectives
1) Find Airidah
You and Yorin have just exited the Weeping Cairns and will need to check the area marked on your map for signs of Airidah.
2) Investigate the disturbance
After walking around for a bit, you will hear screaming nearby and will need to investigate the area just north of where you are.
3) Destroy the Risen Remains
There will be Risen Remains in the area, which is revealed to be Clocheen and you will need to destroy it to clear the area.
4) Defeat the Spirits
Along with the Risen Remains, there will be spirits that will attack you and they will need to be cleared out before you can check the area.
5) Speak with Arlo
A man named Arlo will come out and you will need to speak with him, which later results in Yorin staying behind to protect Arlo and his partner.
6) Find and destroy the Risen Remains
There will be 2 Risen Remains in the area and you will need to cut your way through the corrupted roots blocking the area to reach them.
The Risen Remains will be marked on your map and you will need to head to each of them to clear the areas.
7) Return to Yorin
After you have destroyed both of the Risen Remains, you will need to make your way back to Yorin, who is still at Chlocheen with Arlo.
Speak with Yorin and it will be decided that the three of them leave for Braestaig while you continue the hunt for Airidah. (Quest ends after dialogue)
Harrowed Lament Quest Rewards
Once you have completed the Harrowed Lament quest, you will receive XP, Gold and will be able to continue with a quest called Apex of Misery.
Verdict
Things have gotten out of hand in the area and it looks like Airidah is allowing people to be left vulnerable to the enemies that lurk in the area.
It is confirmed that she is working with Lilith and the demon may be nearby, which is reason enough for the others to leave.
You, on the other hand, will stay behind to find Airidah, who is believed to be at the top of an area known as Solitude.
