Red herring
A red herring was a metaphor derived literary device that intentionally misleads the audience to form a false conclusion detracting from the relevant  of a story. 

While the crew of  tried to exact the location of the yet unknown Azati Prime from Degra, who eventually revealed that his family was on a colony near a red giant,  mused that "this red giant might be a red herring. He only told you his family was living near one of these stars. We don't know that the weapon is there." ()

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Literary devices