How to Complete A Life's Work

To start 'A Life's Work,' go to the southern part of the Observatory in Abbasiyah and find Al-Mahani sitting on a bench. He will ask you to retrieve three scattered pages of his research.

After Al-Mahani attempts to walk with you and collapses, help him up by holding the indicated button. If you encounter a glitch where you cannot interact with him, fast travel away and back to the area.

The first page is located on the building top to your left. Use Eagle Vision to spot it blowing in the wind. Follow it as it blows towards the northern side of the Observatory and lands on another rooftop.

Head to a window on the northern side of the Observatory. You'll find a movable shelf nearby; pull it to the end of the floor indention and climb on top.

Equip throwing knives. Aim through the window at the locked room's door latch until the red indicator appears, then throw a knife to break it.

Enter the Observatory through the main door near Al-Mahani. The second page is upstairs on a table.

For the third page, climb to the top of the Observatory (or fast travel to the viewpoint if unlocked). The final page is on a table.

Use the viewpoint to perform a leap of faith to quickly return to Al-Mahani. You will find him deceased, with his son kneeling beside him.

Speak with Al-Mahani's son and choose whether to lie or tell the truth about his father's last words. This choice does not affect the outcome.

The quest is completed after speaking with the son, rewarding you with a skill point.