Aianon has made a plant in the open airless space above the surface of Thilanushinyel. It is a very, very large plant - some dragons will be attending the party, after all, even if Ansharil in particular is going to be assorted small things and stay on Sarion's person the bulk of the time.
The locals will be Sarion, her beloveds, their other beloved, the five conjured dragons (and their Bondmates, where applicable: Virgivere and Lissa), and Liselen - Magania has, as usual, declined, and so far no Bell party has featured Bell parents.
Amariah is bringing her boyfriend and spontaneous daughter and two of the spontaneous daughter's friends, as well as an Alethian instance of the Rupert template.
Shell Bell is bringing Pearl and Screwdriver.
Golden is bringing her usual large contingent, as usual not including her husband but including her daughter and daughter's grown fosterling (the other remaining at home) and his wolf, both mothers-in-law and one father-in-law, adopted siblings, staff members including the Joker and Nathan, and the children of the aforementioned.
Glass is bringing both wives, all three daughters, Kanim, and her cat. She invited Icarin and Valeria, but their parents are not willing to let them gallivant into other worlds unsupervised and had a scheduling conflict.
Stella's bringing a smattering of people including Alice, Anna, Sandy, Libby, Bridget, her college roommate Janine, and Lazarus.
Tab is bringing Aelise (but not Kers) and Luhan.
Etty is bringing only Nona.
Aether, likewise, brings no one but Celo.
Pattern comes with Ripper, Slipstick, Queenie, and Ghosty.
Aegis is accompanied by her four-bodied boyfriend, Merryweather, Whitlock, and Howlett.
Aurora comes with Brilliance, Lexi with her Device Persica, Agent Honey with her Device Adularia, and Beth.
Rose brings her husband and three children and her former apprentice, Luc.
Angela brings her husband, her four children, several of her friends, and some of those friends' children and grandchildren with and without wings. Keziah also brings a friend.
Juliet shows up with Soph, Minus, Red, Giles, James, Virginia, Minnie, Ike, and Val.
Cam brings Jellybean and Tilly and stops there.
And from unBelled worlds hail additional Sherlocks and Tonies, Darcy, Matilda, Pepper, and Eights.