Help to go in the spring (Ori and the Will of the Wisps)

figured it out myself, had to pull the lever

qurbi4
I have the spring was a strange bug: when after I found Pete stone indicating on a map all the secrets, I decided to knock myself 100%. Only here in the Spring, even after collecting all the secrets, the statistics remained at 99%. I decided to just run the Spring in all possible corners and finding nothing, which of course, if I have all there gathered, the statistics was still 100%. Maybe I just wasn't in one of the empty corners of this location, where to search then nothing, but not having been there in the statistics 100% is not counted. Such a strange bug or just approach the logic of the developers in generating the statistics.