... have the plot and everything in my mind, here's basically what the story is about:

guy A wakes up on the streets and doesn't know what happened or where he is. guy B is also there, who turns out to be an angel from above and tells him he's dead

guy A doesn't want to wander among the living and wishes to find peace. guy B tells him he has to find his soulmate. they eventually find a prostitute who turns out to be guy A's soulmate but there was another thing, he has to kill her in order to find peace. the reason to this is that soulmates can't rest in peace if one of them is still alive. so here's where guy A finds himself not knowing what to do.

there are plenty of books called "soulmates", so I would appreciate it if you could help me come up with a (preferably) short title. thanks a lot