Here's the official synopsis at any rate:

“Strange rumors start to spread at the Catholic girls’ high school after Unjoo committed suicide one night. Unjoo’s younger sister Jung-un who attends the same school gets suspicious about Unjoo’s death. After persistent investigation, Jung-un finds out that on the night of the incident, Soy [me: ? Soy?] Eugene, Eun-young, Unjoo, the four of them had tried to commit a joint suicide after making a vow on blood. But the three are still alive, and only Unjoo had died. the desire, jealousy, and lies behind the pledge of death between the four girls are revealed, along with the hidden truth behind Unjoo’s suicide.”

(Something tells me we missed konglish by a hair's breadth.)

Unlike your typical, interminable American horror flick franchise (Saw being a rather spectacular instance of this utterly cynical and exploitative phenomenon, but hey, cinema is about making money too, I suppose), Whispering Corridors doesn't involve a continuing plot (or gimmick, one might say) or overlapping character - and therefore doesn't feature recurring cast members. Instead, the series takes its name after its context, in this case the “Girls' High School” (which is the literal translation of (Yeogo goedam, 여고괴담) in which all the  bloody fun is taking place.

The four films released so far have all been above average and enjoyable to varying degress, depending on what you're expecting to get from them. The first three, Whispering Corridors, Memento Mori and Wishing Stairs were released by Tartan as The Ghost School Trilogy in a 4-disc boxset back in late 2007.  The fourth film, Voice, was released in the middle of last year by Genius Entertainment, with a rather misleading cover by the way (my guess is that they were trying to sell it as a gorefest, which it isn't).

Part 1, as is customary for the inaugural film of a franchise, was a strong, well-written horror film that found a twisted way of inserting some scathing criticism of the Korean educational system. It pretty much set the tone and a template for the rest of the series, in the sense that they were all, one way or another, about something more than just creepy girls with long black hair. Part 2 (Memento Mori) got praised to the high heavens, a little excessively, I think. I didn't really buy the lesbian subtext/storyline, but visually, it's certainly the most interesting. I missed Part 3 (Wishing Stairs), so no comments. As for Part 4 (Ghost Voice), I liked it... as far as I can remember: it's been slowly fading from my fallible memory.