optics - Fate of light ray

This question has been on my mind since I first learned optics. Where will the light ray go?

First, I thought of it taking a U turn. But, I don't think that will happen. Now I have studied a bit about wave optics and I think that the light will go... everywhere? Can someone please explain it in realm of ray optics? I wouldn't mind a bit about wave optics. Just don't go deep down there.

Thanks.