For several long, tense moments, Iris stood staring in the direction Barry had disappeared in, one hand held out as if to reach for him. Kara found herself holding her breath, waiting for the moment that Iris would turn around and confront her for her role in recent events.
"What the hell is happening?" Iris demanded a moment later, turning on her heel to face Kara.
"It's… a long story," Kara replied. She kept her face turned away from Iris as she spoke. She couldn't disguise her voice the way Barry could, and she didn't wear a hood and mask that cast her face into shadow that would conceal her identity the way Oliver did. As astute and sharply observant as Iris was, she was sure that she would recognize her at any moment, and she thought it best to prolong that moment for as long as possible.
"I've got time," Iris said sharply, settling into a confrontational posture and crossing her arms in front of her chest.
"The man in yellow…" Kara said, trailing off for a moment before she found the right words and went on, "we call him the Reverse Flash, and he, um… he's from the future. Centuries in the future, in fact. His real name is Eobard Thawne."
"Thawne?" Iris asked. "Like Eddie?" Kara nodded.
"Turns out Eddie is an ancestor of his," she said.
"So then why kidnap him?" Iris asked.
"Insurance, I'd guess," Kara replied with a shrug. "You see, we set a trap for the man in yellow, but he knew about it the whole time, and it failed. Then he went after you, and when Barry stopped him from killing you, he took Eddie in order to keep Barry so busy trying to find him and bring him home like he promised you he would that he won't be able to interfere with whatever he's planning next." This was mostly conjecture, but Kara suspected no less true for being that. She'd become quite adept at drawing conclusions quickly, sometimes with very little information to work with.
"You know," Iris said after a long pause, "it's kind of rude to not look at someone when you talk to them." Kara chanced turning her head toward her, but kept it tilted downwards, trying to keep her face hidden behind the curtain of her hair. Again, she wished for a hood like Oliver's to cast her face in shadow. Idly, distractedly, she wondered if she should ask Cisco to add one to her suit for her once this was all over. Granted, people didn't often see her up close like this, but it couldn't hurt to be prepared in case it ever happened.
Iris' sudden gasp interrupted her idle musings.
"Kara?" she cried. "Kara?!" Kara winced.
"I suppose there's no more point in keeping up the charade anymore, is there?" she asked, tossing her hair back and facing Iris full on for the first time as Supergirl. Iris just shook her head.
"You're Supergirl?" she asked, Kara suspected more because she was still trying to wrap her mind around it than because she actually needed confirmation. "Why didn't you tell me?"
"If I had, would you have believed me?" Kara countered. "Would you have believed that Kara Allen, reporter for the Central City Sentinel, was a superhero?"
"I suppose not," Iris conceded, shaking her head. After a pause, she went on, "Wait, if you're Supergirl, then you've known that Barry was the Flash this whole time. Why didn't you tell me that?" To this, Kara could not think of an answer that Iris would believe or find acceptable, so she defaulted to the same one that Felicity gave to anyone who asked her who the Arrow was- "It's not my secret to tell."
"I guess I can't argue with that," Iris said. "Though, believe me, I want to…" She trailed off, turning back to stare in the direction Barry had run off in once more, as if she thought she could make him appear with Eddie in tow by doing so.
"Barry and I are going to have a lot we need to talk about when I see him again," she said, mostly to herself, and Kara could only nod in response.