Blood and Shadows is a brief main quest in Assassin’s Creed Mirage.
Your objective is to find and speak to Fuladh in Karkh.
Here’s a walkthrough and guide of Blood and Shadows in AC Mirage.
Find and speak to Fuladh
Head to Karkh. Look for Fuladh in the Bureau there.
The location is shown in the map below, marked by the quest symbol.
When you get there, use Enkidu to pinpoint the exact location of the Bureau.
Enter the Sharqiyah Bureau and meet Fuladh and Ali inside. The quest ends here.