First off, some backstory. One of my players accidentally killed 25,000 people & the center of culture for this continent by dropping a hyper-intelligent ooze on the largest city in the area. This player didn't expect this outcome because he was tricked pretty good. He and the rest of the group then were put on trial and imprisoned for 14 years. Because they believe that this a fair punishment, the PCs are in prison and don't plan to escape.
I guess I could just role play the passing of the next 14 (in-game) years in prison… What are my options to deal with a disruption like this to my planned campaign? What are the pros and cons of coming up with a Deus Ex Machina versus this being our new campaign premise now?