Atmospheric and just enough in length for the story it wants to present.

The drama starts slow, by presenting the setting- a boarding school only for the best students, the characters - the few students who stay at the shut down school for the holidays, and the mystery-letters sent to all of them with the same massage. From then on, the story is packed with thrill, good performances, action, mystery and suspense. The only problem with the series was that it didn't explore the impacked the "adventure" had on the students after it was over more in depth.

So, 8 out of 10.