What's the worst case of deus ex machina you've ever seen?

Definition of Deus Ex Machina: "when some new event, character, ability, or object solves a seemingly unsolvable problem in a sudden, unexpected way. It's often used as the solution to what is called "writing yourself into a corner," where the problem is so extreme that nothing in the established setting suggests that there is a logical way for the characters to escape."

copied from Tv Tropes.