You must obtain seeds from the flower-man. He will give it to you when you bring him the veronica from the lighthouse. Put the seeds in the ground below window.

You must travel to the lighthouse and turn off the light. Then you get the plant/tree, deliver to the flower-man. He gives you the seeds.

I am at the same level. But only have helmet and breast armor. Where are the third part?

You collect the handle, and two crystals. Then the strange device shows a puzzle which I didn't find any logic in. Anyway, I got to leave, and now I am in the caves.

You climb to the window when you plant your seeds on the ground below the window. I am now in the caves, and trying to get past the fire. Got armor, but don't find a way to use it. Anyone?