Lascaux: The Axial Gallery: Event Horizon
The third warning comes from the two goats. The symbols are:
kǒu (see image), meaning mouth or edge (archaic);
gǔn丨, meaning downward movement or drop, and;
gǔn丨, meaning downward movement or drop.
Perhaps they are referring to the inner event horizon. Within the boundary of the inner event horizon, the gravitational pull is so strong, it makes escape impossible.
Author's Note
The beauty of Cave Script is that you don’t need a modern dictionary definition for each composite character. You just look at the component parts to work out the meaning.
References
Image Credits:
Les bouquetins affrontés. Paroi Droite. Diverticule Axial: Norbert Aujoulat © MCC-CNP, 2004: Lascaux, le geste, l’espace et le temps, Paris, Le Seuil: Visite de la Grotte: Ministry of Culture, France: http://www.lascaux.culture.fr/#/fr/mediatheque.xml/39
Small seal script character: Shuowenjiezi: research tool in Chinese traditional philology: http://www.shuowenjiezi.com/