Okay, so Greenlee found digitalis in Ryan's jacket. My guess for how this is going to play out? They will do something stupid like David killed himself and tried to frame Ryan for it. They will try to spin it by saying that David thought there was no reason to live without Greenlee, but he was going to make sure that no one else had her, especially Ryan.
The show just feels so empty without him and the writers are going to need to step up their game if they want viewers to be entertained without the important series regular alive anymore. Hopefully the show can step up to the challenge; today's episode definitely proved they can as I was as thoroughly entertained by a Tuesday episode as I could possibly be.