My main character was off doing something else, so for a single session I joined the party as a drunken gunslinger who helped them take down a dictator out of boredom. She kept running off and trying to blow things up.
When finally the druid told her she COULD blow up a warship, she snuck on board, fired a cannon at another warship, and hit its gun powder, blowing up that ship. But because it was a nat 20, the cannon ball continued through the other ship to hit the castle the party was trying to siege. Satisfied, the gunslinger then ran a fuse out the window of the ship she was on, light it, and jumped just before the explosion.
All the party saw was the series of explosions. None of them know that she swam to the docks, got on a sailing boat with a gnoll, and literally sailed off into the sunset.