Spoilers in this, if you haven't seen the episode yet.
Episode 2: Yakusamashi-hen (The Disaster Awakening Chapter) Part 1 - Playing Tag
The start of the first of the 3 major arcs in this series of Higurashi, and one specifically written for television (in other words, not an arc that was used in the game). Higurashi creator Ryukishi07 requested that this arc be created to fill in some of the plot gaps left out in the first series, using some of the "Tips" from the game (extra bits of text information covering things that may or may not be pertinent to wtf is going on). As there are 23 episodes left in this season, this means that Yakusamashi-hen is likely to be no shorter than 7 episodes long. Long arc is long.
And as usual, the arc starts off with the classic "happy episode" before everything goes to crap. We have Rika, talking in her "Dark Rika" voice to someone who isn't there [spoiler](actually, they are.... they practically spoiler this by having the other
silent participant in her conversation appear in the opening credits and the next episode previews, but I digress)[/spoiler] whilst downing a glass of wine. We have Satoko taking regular injections (the kind Rika keeps trying to use of people who go psycho in other chapters). Then we have Satoko in combat with Keiichi, first being defended by Shion, who appears to have done a 180 in her relationship with Satoko (she tied up and stabbed the girl to death in Meakashi-hen), probably because she subconsciously remembers her promise to Satoshi to protect Satoko, and then Satoko finally "aiding" Keiichi into getting deep in the merde with the class teacher.
And then we have the zombie-tag game, in which everyone who gets caught by the person who is "it" (in this case, Satoko) becomes a zombie and joins her in the hunt for others. This takes up the largest portion of the episode, so basically it is 15 minutes of amusing character-building as Keiichi gets betrayed again and again, first by Rika, then by Mion and finally by Rena.
This is followed by the losers' punishment, which is particularly bad in Keiichi's case as he has to dress up in a swan outfit, including suggestively-placed swan's head and neck, followed by the usual meeting with Takano and Tomitake and the retelling of the story about the murders in Hinamizawa, which particularly effects Rika. End of episode.
Creepy around the edges. We all know it won't last. This arc makes it look as if either Satoko or Rika will be the ones who will "lose" it and go postal on the rest of the cast before everyone dies. Again.