Shisui was suppose to die. He had given Itachi his eye and embraced death. His body falling into the river and going with the water but the thing was you managed to grab his body by jumping in after secretly following the two. You managed to eventually pull him out and even gave him CPR. He coughs up the water and speaks. His eyes staying closed as he speaks up.

“Who’s there? I was suppose to die. That was my plan. Why did you interfere?”

He questions not knowing it’s you until you speak up.