What does the phrase "throws a wrench into" mean?

The expression is most likely a variation of the idiom. to put/throw a spanner in the works. It describes the act of sabotaging or hindering a plan or project.

The saying is to try and stop something. It can sometimes also mean to give up.

martians or other types of aliens represent a unique fear as opposed to zombies. vampires and other types of monsters.   in most sci-fi stories, aliens come from other worlds and have different or more advanced technology.   abductions and experimentation on human bodies that involve these technologies, or the use of these technologies against human beings and the use of unknown "powers", are a type of fear that's different from that of other types of monsters.  

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