Complex sentence: The Goa'uld Nirrti uses an Ancient DNA Resequencer to experiment on SG-1 in "Metamorphosis", and finds out that Jonas is different from other humans; however, she is killed before this is further investigated.
Split into simpler sentences: The Goa'uld Nirrti captures SG-1 in "Metamorphosis" and experiments on them using an Ancient DNA Resequencer. She finds out that Jonas is different from other humans, but she is killed before this is further investigated.