1) Yusif was there when Z was in the fire and he quite possibly set it.
2) This is not an attempt to get Z back, but more an attempt to bring revenge on Z and Mas
3) One of the Masood clan will be trapped in a house set alight by Yusif (with Afia inside as well) and Tamwar will have to come to the rescue.
4) Yusif will die as a result of the fire

Those are my thoughts. Any others?