Memento mortis convallis - poetic walking simulator. Human intervention and extraction resulted in the uncovering of trilobite fossils near Prokopské údolí, southwest from Prague. Besides the construction material and a few research results from the fossils, ghosts awake from their long sleep pressed between Devonian layers. The ghosts of trilobites speak to the visitor. Tell a warning tale about extinction, that is brought about not maleficent greed, but simply effectivity. Art piece for interactive game environment.