This volume is split into four chapters, including the prologue chapter. It does not contain a complete story however, as it is "to be continued" on the next volume, "Suzumiya Haruhi no Kyougaku."
The source of all the events for this story is the appearance of Kyon's Jr. High friend, Sasaki. The two haven't met since they graduated from Jr. High, and since a new school year has just started, their chance meeting marks about one year. Of course, it's not a random luck that they met again. Haruhi is uncertain about her own stance regarding Sasaki, at least subconsciously, causing Koizumi some extra part time work headaches. Worse yet, Sasaki's sudden appearance is linked to the other set of organizations.
Speaking of the other organizations, names of some of the members of those organizations are finally disclosed. The other supernatural girl (vs. Koizumi) is Tachibana Kyouko, that bastard future dude (vs. Asahina) is Fujiwara, and finally (and for the first time) making her appearance is Suou Kuyou of that unexplained alien organization (vs. Nagato).
Starting at around half way through this volume, you're given two parallel stories to read, happening at the same time periods, but in different parallel universes. I'm guessing that we'll get to meet the person from another parallel universe sometime soon. Once that happens, SOS-dan would be complete, since that's what Haruhi asked for from the beginning, "an alien, a time traveller, a person with supernatural powers, and a person from a different universe."
Things are really starting to move, but it's obvious there's more to come because there's still another character who is only mentioned without a full appearance yet. I believe she is to be that person from a difference parallel universe.
By the way, did I mention Sasaki is female? And a cute one, too.
