Complex sentence: During the interrogation, it is revealed that the two artifacts (the gold and the silver one) are the keys to a Votan ship buried in the mines, carrying a weapon capable of killing entire species, and the real reason E-Rep is interested in Defiance.
Split into simpler sentences: During the interrogation, it's revealed that the two gold and silver artifacts are the keys to a Votan ship buried in the mines. The ship carries a weapon capable of killing an entire species, and it's the real reason E-Rep is interested in Defiance.