"Nibiru" was the sixteenth "unofficial" episode of Star Trek: Phoenix-X and the fourteenth "unofficial" episode of the fifth season. It was the sixteenth Star Trek: Phoenix-X entry for the Star Trek Online: Unofficial Literary Challenge and was the only Star trek: Phoenix-X entry for the twentieth challenge of those unofficial challenges. It was the first entry to focus on five ships of Task Force Epsilon, including all ships which have appeared thus far in Star Trek: Phoenix-X entries for the Star Trek Online: Unofficial Literary Challenge. The story is comprised of three 'parts' and is completed.