If the events in 'The Impossible Astronaut' indeed show River Song killing The Doctor (in the astronaut suit), if this is the event that leads to her impisonment in The Stormcage - how did she end up in a 51st century prison for a crime committed in 2011?
Wouldn't it be appropriate if she was followed back in time by a Time Agent and arrested?
The Time Agents we are told in 'The Empty Child' are based out of the 51st Century.
Is it a coincidence that the century River Song is imprisoned in is the same century the Time Agents are based out of?
Also keep in mind, 'The Empty Child' was written by a writer named - Steven Moffat.
What if the agent that arrests River Song is our favorite Time Agent, Jack Harkness. Jack Harkness, a character introduced in a Steven Moffat episode. Jack Harkness, a characted Steven Moffat stated he'd like to bring back to his series of Doctor Who.
Also, one of the mysteries introduced in 'The Empty Child' was that Jack Harkness quit the Time Agent because he had lost two years worth of his memories. Were these memories of The Doctor that needed to be removed so he wouldn't recongnize The Doctor when he met him in his future during 'The Empty Child'?
Wouldn't this just bring Steven Moffat's story arc full circle.
Time-Wimey. All speculation on my part, but I'd pay to see it happen.
You read it here first.