"And we find ourselves at another one of Ophiuchus' little themed puzzle dinners," you say while glancing at the other seven people.
"I really like its puzzle dinners, honestly," Sagittarius admits, "though I was never good at figuring out its secret themes in the past."
"One just needs to be observant," Gemini smiles. "Ophiuchus always designs the seating plan to fit the theme. Speaking of which, we did not receive a fixed seating plan this time, did we?"
"Nope. This time, Ophiuchus decided to make the seating plan a puzzle as well itself. Ophiuchus does like adding puzzles to its already puzzling dinners." It is well-known among the group that Pisces is not a fan of puzzles. "As if guessing the theme of the dinner is not difficult enough. Speaking of the seating plan, what are the rules again?"
"Wait, I'll remind everyone of the rules," Virgo read the email Ophiuchus sent to everyone an hour earlier. "Here they are..."
- There is one person sitting right between Gemini and Sagittarius.
- Cancer sits right next to Libra.
- Libra does not sit right next to Virgo.
- Sagittarius does not sit on the immediate right of Aries.
- Pisces sits directly across from Libra.
- Gemini sit directly across from Virgo.
"And you," Virgo turns to you with eyes sparkling...
- You are sitting on my immediate right.
Aries is the fastest solver among the group. "I can work out two solutions. Any preferences which one we should go for?" it asks, while proudly showing its solutions on a piece of napkin.
"I prefer the side further from the fireplace," Cancer mutters. "After all, our group tends to get too warm very quickly."
"Weird theme, isn't it?" Virgo asks after delicately pulling in its chair. "I wonder what Ophiuchus thinks we eight have in common..."
You politely nod. Your eyes glance from left to right. How does this seating plan reflect the theme...?
"Why are there only eight people here in this party?" you overhear Cancer asking Libra. "I know Ophiuchus never attends these parties it organizes, but what about the other four?"
"Well, two of them were never even invited in the first place," Libra replies. "It is a bit mean, but Ophiuchus told them they do not fit the theme."
"And what about the last two who did get invited?" Cancer inquires.
"Oh, those two turned down the invitation very early. One of them already had plans to go diving in the sea it lives close to. The other is the ruling zodiac sign tonight, so it is too busy sorting out the paperwork and meeting up with the other gods. Surprisingly, Ophiuchus is quite pleased about all this." Libra's grin grows larger. "Ophiuchus told me this fits the theme even better, and brings an element of balance to the table, which as you know, is something I cannot complain about."
You stand up abruptly. Seven pairs of eyes stare back at you.
"I know the theme of this dinner party," you smugly announce.
Question: Who is the ruling zodiac sign tonight?