In story telling, there is a line it slowly escalates up, at a point goes up to certain point then goes down fast, what is the highest point called?

it is called the climax of the story. 

The highest point in story called node ( الحبكة )  which shows the problem or where the story reaches  it peak then it goas slowly to the solution

I think you are talking about the "climax", the highest point of interest or suspense in a story.

That line is called Reaching the Climax and the highest point is called the Climax of the story

It's the climax of the story. I suppose you already knew the answer but you just ask for the sake of asking.