A Quinta Dimensão

Throughout its history Earth found itself cyclically dipped in catastrophic episodes of various kinds (cosmic, climatic, epidemic, human made). If these episodes caused the extinction of thousands of species, they also have created the opportunity for the emergence of new species. The most recent of which caused Earth the most recent and almost fatal cataclysm.
Confined to a few niches, humanity was suddenly close to extinction and deprived of almost all of its memory. This opened space to archeology to become the most supported of all scientific spheres.
On that obsessive search for the lost memory, one group of scientists unearths from the bowels of the planet a coded record. After deciphering it, they felt irresistibly tempted, by default of the authorities, to follow the instructions it seemed to contain.
What would these instructions lead them to do? Was it a revelation? Or a Guide to build a machine? For what purpose? Would it be ancient human or alien? Would it be a spaceship, capable to get them to go through the extensive canyons that mediate the stars? Or would it be the long dreamed time machine, which would lead them to travel since the turbulent birth of the beloved Earth until their ultimate breath? Or was it merely a communication device? Maybe just an observation device? Could it be a gateway to trigger an invasion of planet Earth? Could it have been precisely the attempt of its construction what triggered the most recent disaster?