: Rose begins to believe the ash contains spores from an "Ancestor," the oldest organism on Earth.

: Cat reveals to Rose and Heather that she is pregnant. You can watch this episode on Amazon Prime Video.

: A direct download from the Amazon servers without re-encoding, preserving the original streaming quality. H264 : The video compression codec used. DDP : Digital Dolby Plus, the audio format. Episode 4 Summary

: Includes multiple audio tracks (usually different languages). 1080p : High-definition resolution (1920x1080 pixels).