River Song was an alternate version of Melody Pond who hailed from a parallel universe.
Biography[]
Early incarnations[]
She assassinated her universe's version of the Doctor, before turning on her captors during the Massacre of Demon's Run. When she would later recount the incident, she would admit she didn't even know the Doctor's name. She acquired a TARDIS and began travelling the universe, living through multiple incarnations including one resembling the River Song of the Doctor's universe, but soon found she was being pursued by the Karla-Gard. (AUDIO: The Two Rivers)
Visit to the Doctor's universe[]
She accidentally slipped through into the Doctor's universe via the Bridge, a tear in dimensions, where she encountered an alternate version of herself. By that point she had gone through a number of her regenerations. Together they visited Professor Dern in scenes across her life, from adulthood to infancy, as "Mrs and Mrs Nim".
The two Rivers finally defeated the Karla-Gard by creating a paradox, deciding never to inspire the young Profesor Dern to embark on her expedition to the Tomb of River Song. (AUDIO: The Two Rivers)
Continuing adventures[]
River successfully returned to her own universe, where she sought out her own world's Professor Dern, taking her on as a companion. (AUDIO: The Two Rivers)