Complex sentence: Daniel is able to reconstruct P4X-639's Ancient history with the finished translations; the Ancients had attempted to escape an unidentified disaster by building a time machine but never got it to work properly.
Split into simpler sentences: Daniel is able to reconstruct P4X-639's Ancient history with the finished translations. The Ancients had attempted to escape an unidentified disaster by building a time machine, but they never got it to work properly.