[Delvo]

The actress who played River in "Firefly" is playing a robot that's here to protect John, and apparently will hang around long-term... which implies that there must be something major to protect him from, apparently a long-term supply of them... which makes me suspect something else that came from the future because those threats are bigger and more dramatic and more big-story-related than the threats from the present.

This is probably going to be like the way the Stargate and Highlander TV shows were based on their original movies: with some little but important detail in the original movie altered for the series and no attention paid to sequels at all... sort of an "alternate universe" interpretation of the concept, or the way superhero comic books get restarted occasionally with changes that contradict the way the same superhero and his/her world had been presented before.