Water Carrier

The candidate fill with water a transparent tube open at its ends which he must seal with the palms of his hands. With this tube, he will have to cross an electrical transformer by crawling, twisting or stepping over obstacles to the bottom of the cell, At the end of the course, he will find 3 pipes where he will have to pour his water. With a correctly filled tube, 2 trips may be enough to fill the 3 pipes and thus recover the key. On each return, the candidate does not have to go through the transformer again and can take a corridor along the wall to return to the starting point.