New discoveries uncover the secrets of the universe's strange alien worlds that could be home to extraterrestrial life. This is a mashup of "Space's Deepest Secrets", S04E04, "Journey to Alien Earths" and "How the Universe Works", S05E08, "Strangest Alien Worlds".

New discoveries reveal the secrets of black holes, the universe's most dangerous and mysterious phenomenon. This is a mashup of "Space's Deepest Secrets", S04E05, "Wrath of the Black Hole" and S02E03, "Black Holes: The Einstein Prophecy".