It was good until.... The movie is a usual murder mystery, with a good setup - eccentric billionaire, his gang of friends / enemies on a isolated Island with our detective. It was indeed engaging with the layers revealing like a onion.

The reveal of the middle act was superb and the flashback was just superb twist to the tale. But the movie ended like a onion. There is nothing at the end.

But, it is a rare movie that just truly limited detective as a detective and not a all out heroic problem solver. Nothing more to add. Had the last act been cinematic, it would be much much better mystery movie!!