I’m still asking myself how the Doctor from the past (AD 102) could save himself from his future by giving the Rory auton the sonic– because a Doctor trapped in the Pandorica wouldn’t have something like a “future”, how could he? He’s trapped in there and that’s just it. End of. Even a handsome time agent’s Vortex Manipulator (if of or off the wrist) couldn’t have helped him out of there – how would he’ve managed to touch it while his hands were captivated?
But what even is more exciting – how did the (slimy) sonic got on the table in the (hidden) room of Amy’s house? Even if the Doctor would have lost it by accident (he never would– would he???) the device hadn’t been found on the table but on the floor. Anyway. I can’t see (by now) where this will lead us, so let’s forget about it. Although… who IS Prisoner Zero? The Doctor???
By now, I can’t really see any connection to the empty duck pond, but ever since Donna’s mentioned the disappeared bees (which is sysonymical for an Earth dying) there has to be a greater context– because Steve Moffat isn’t affiliated to pay attention to or wasting time on such as negligibilities.
And somehow it just came to my strange mind: What if River Song weren’t the Doctor’s future wife nor his mother… but his daughter?!
[ADD: Maybe this already was on discussion. If so, please send a note, I’ll remove my comment at once.]