SEGA announces a new update is now live in Total War: ROME II, adding a Halloween celebration to Creative Assembly's RTS sequel. There are no details about this on their haphazard news page, but it is discussed in their Rally Point video Episode 22, which also covers the upcoming ATTILA expansion. Here's word on the patch:

Live now, the latest free update for Total War™: ROME II adds the festival of Lemuria to the game and a new seasonal challenge, Nightmare Mode!

Lemuria was an ancient feast during which restless spirits were exorcised from the home with the alternate offering of beans and then clashing of cooking pots. Perhaps an early Roman version of Trick or Treat?

Nightmare Mode can be toggled on from the game options menu, causing your troops to suffer horrifying visions in battle. Harpies descend from the skies as a terrifying atmosphere envelopes your forces. Assailed by such apparitions it is no surprise that your soldiers will find the enemy extremely frightening!

Any generals skilled enough to complete a Campaign battle in Nightmare Mode will earn a new Steam achievement and the adoration of their peers. May the gods help you if you try to complete a whole campaign…