Natasha
Steve had walked back out to the living room where everyone was still hovering around in shock. They'd all managed to re-read the unusually short briefing packet before awkwardly standing around; waiting on Captain America, needing Steve's natural leadership to re-stabilize the tower's suddenly even more off kilter atmosphere. But when Steve reappeared, not even he seemed to know what to do.
"So how did you convince this kid again?" Tony suddenly blurted out. Steve shrugged looking confused.
"I didn't. I saw him on my run and he was visiting someone's grave. Then out of nowhere some kid walks up to him and tells him he has to join us. Percy said yes. And... here we are." As Steve finished speaking Natasha felt something inside her click back into place and then the Black Widow snapped back into place; the room and it's occupants coming back into stark relief under her clinical assessment. She stood up.
"Something's off about this kid. He didn't change his mind for kicks and giggles. We need to keep a close eye on him." Natasha pointed to Steve. "And you get to test him first." The tensions broken, everyone laughing as Steve frowned slightly but didn't argue.