OKay, so, my guesses:
7.19
At the end Ryan gets kidnapped
7.20
Supposedly, Ryan is show cleaning his wounds at the beginning, but then I don't know where the Promotional pictures fit in, but they just MIGHT be flashbacks. Or maybe, Ryan finishes up doing the bad guys' biddings, then goes to get Billy himself, ends up getting captured again, and then Horatio comes in and saves the day.
Tooooo many theories.
There are a lot of theories,but I have the very same ones that you do.I also wondered if Ryan is kidnapped a second time(see my post above)
and Horatio saves Billy.
From the spoilers I saw, he gets kidnapped at the end of 719 but I don't think he is actually missing per se. I think as far as the team is concerned he tells him he is somewhere so they don't come looking.... b/c he is abducted via a flat tire to his hummer and then in the spoilers I read we see his phone vibrating b/c Eric is trying to call him and the person who abducted him, grabs the phone....the spoilers cut off there but I am thinking that Ryan is told to come up with an excuse so the team doesn't get suspicious.....once they are done beating the crap out of him they let him go b/c he they need him to be working the case etc.
So the pics we see for ep 720 could be part of a flashback sequence that we see of his abduction.....I don't think he gets re-abducted. From the spoilers H learns what is going on from Billy's dad and he sets off on his own to find out what happened to Ryan and Billy. While H is doing this, Ryan is still working the case. That is how *I* understood and read the spoilers.
At this point, until we see the ep....anything is possible