Given a sentence, generate a most likely context or previous statement. The previous statement should be relevant to the given statement.

Someone collapses to his knees, then falls face down on the floor.
Someone yanks out a handful of green goo.

He searches for the gun.
Someone leaps to his feet.

He stops out of sight of the passersby on the sidewalk and scrutinizes his wrist where the web shot from.
Someone runs across a street intersection and comes to a gateway leading into an alley.