All of a sudden
Definition 1 of 1
Pro Tip 1/3Unexpected Events
Used when something happens without prediction or signs, often surprising. 
All of a sudden, a deer jumped onto the road.
Pro Tip 2/3Narrative Twist
Frequently used in stories to describe a quick change in action or plot. 
All of a sudden, the quiet village was invaded by bandits.
Pro Tip 3/3Dramatic Impact
Enhances the drama of a situation when retelling events. 
He was fine and then all of a sudden, he fainted.