Re: Before 7:34pm. 616 Sam just went coz it's a big social event and he's friendly, he doesn't actually really know what bonfire night is, like... about.
Elsa obviously had to go so she could see the results of her and River's shopping.
Ianto was there to be all British and make jokes about colonials, because he's kind of a dick.
TJ is mostly just sort of sitting around watching.
Aracely normally would but she's still feeling really bad about letting her mogwai gremlin-ise so she's conspicuous by her absence.