Lex's clone stood at the edge of the waterfall, observing the crystal clear liquid falling down with loud fury. On Earth, glacier water was usually considered one of the purest sources of water available. Here, glacier water held residual taint from some long forgotten contamination, making the water extremely aggressive in nature and dangerous to touch - not that Lex was considering bathing in that water or something.
Behind the waterfall, an arch was visible, coincidentally the perfect size to allow Lex through. But through the arch, he could only see shadows, as if it led to an unlit path.
Carefully, so as to not disturb the waterfall, Lex made his way around the water, and approached the arch, stepping in.
Fortunately, nothing crazy or abrupt happened. The arch leading back to the same waterfall was still behind him, and just to be sure, he stepped out and back in a few times. The arch stayed in place, and nothing in the surroundings changed.
