Its a plural possesive because of the -es and the apostrophe
If a story has an unreliable narrator, you should still trust what they say, although you must take it with a grain of salt. The narrator could still be telling the truth, although if they are insane they may describe seeing a ghost when there wasn't really a ghost. An unreliable narrator does not create a fake story, only an unreliable story, where there may be holes or lies weaved into truth.
