Red herrings

A red herrings is an aspect of stories that is meant to mislead the reader into thinking something that isn't true, such as a double agent whose motives aren't revealed until later on in the plot. The origin of the term 'red herring' came from it's use in the 1600s as something dropped by fugitives to mislead the hounds used to track them (as the hounds would end up following the scent of the red herring instead of the fugitive).