"Deus ex machina" - "God from the machine"
A deus ex machina, or improbable solution to an impossibility, usually occurs in movies when the plot is highly convoluted, and then something (or someone) emerges at the very end and resolves everything. It’s sometimes considered a cheap or easy approach to tie up loose ends in movies or literature. It originates from Greek plays when gods, by descending from above, would clean up the mess that mankind had created.