This series so far is a lot better and more fun than The Silver Eyes (which drove me mad). There are occasional leaps of logic, but these are just kind of spooky Goosebumps-y short stories for teens, so it's mostly forgivable.

I don't think you really *need* to know anything about the Five Nights series to get into these, but... I'd say it's a better experience if you do. Everything is a reference to it.