I'm betting (but don't want to know for sure -- don't tell me, a friend and I are gonna play it) that the recently-released Saw: The Video Game, at long last, ties off the plot of Dr. Lawrence Gordon, originally played by Cary Elwes in the original Saw.
In 2004, Elwesm supposedly at the prodding of his lawyer, sued Twisted Pictures for some unpaid back end, which caused bad blood between the actor and the films' producers. He eventually retracted the lawsuit, citing the lawyer's insistence and publicly stating he regretted it, but the damage was already done. Despite references to Dr. Gordon in almost all of the subsequent sequels, the actor is never seen or heard from again -- in Saw III brief vocal snippets are voiced by someone else and the character's face is covered when we see his unconscious body in the infamous bathroom, and in all of the other sequels, the character is neither seen or heard, only mentioned by others in passing.
Having just returned from Saw VI, I wonder how different the films would be if Dr. Gordon had made some sort of return appearance. Would they dispatched him in just a few minutes, or taken the time to weave Dr. Gordon into the plotline of each new film? Admittedly, he looks pretty boned at the end of Saw, but the franchise has begun to make a point of overturning every rock the camera even glanced at in order to add more strands to an ever-growing web of connections and plot twists.
In the event that the book, shockingly, is not closed by the video game, I wonder if the producers will ever let bygones be bygones and allow Dr. Gordon to make a reappearance. Historically, he seemed to be at the front of fans' minds when it came to the series, and the producers are kicking over the last few rocks. If there's only one more Saw movie (something I wouldn't bet on), I'd like it to go out with a bang -- or perhaps, more fittingly, put its best foot forward.