Creation; a catalyst makes something happen.
To "cause" is an action that makes something happen.
"Cause" is the action word that makes something happen.
To "Cause" is a five letter action word makes something happen.
A stimulus is an event or action that makes something else happen. Other possible answers are trigger or impetus.
Cause.
It could be a catalyst.
In order to be a story character, a person or thing must have things happen to them, and must be essential to the story.
Earings your husband gave you
magicians; mistletoe; memories; mom
bong bong bong
Art? Apples? Anyone? Ants? Animals?
Being stuck in the toilet! LOL