Re: IC/OOC SPACE.
Sam will react very quickly after things kick off to turn his attention to Bucky. He's already figured out that there's something weird going on with Bucky and will quickly connect that, the stories about what people have been doing to the Hosts, Robert Ford's apparent sadness about it, and everything tying together with the Hosts mutinying. He's also momentarily very relieved that Bucky is not supersoldiered this week because he doesn't want to have to fight the Winter Soldier again if Bucky turns out to be affected.
Ianto is turning on the humans, which should be a fun existential crisis for him later considering the whole Cybermen thing. He was probably loitering near the edges of the crowd by himself, so hopefully no one decided to come up and start a conversation with him during the preamble as they're going to be in prime position to suddenly be a target. Otherwise he'll put out his gun and start shooting. He has no expression and won't respond verbally to anything.
Melissa's first instinct is to try to throw up shields before remembering she doesn't have her powers, so to anyone around her it will look like she's just screaming in shock. When she realises it's not going to work she'll throw herself down to take cover and then start trying to move between hiding places across the room to get to safety, ideally being able to grab at least a couple of people along the way.
Kira ducks as well and unsheathes her sword, but it's a close range weapon and she doesn't exactly want to get in close range when she can't really tell what's going on or even which side she should be on. She can be easily persuaded to either run or, potentially, join a side, though will obviously not act against Derlethians at all. It's the locals she isn't sure about.
Laura pulls two of her guns out, but doesn't immediately start shooting. She heard some of the stories people were telling and isn't actually too keen on protecting the individuals she'd particularly noticed. On the whole she feels a lot more sympathy for the Hosts and is likely to even intervene on their behalf if she spots one in danger from someone she knows was spouting off, but otherwise will only defend herself and others from Derleth. She's not going to actively take a side in a major way.