Her name was unique, to say the least. The Cap's first thought was that it must be a code name — like Hawkeye, or Black Widow.

But when Root calls RED housing slums, and in that special tone of voice, a small, wary grin forms on Steve's face. He might not understand that she's flirting (because Steve is as dense as a someone could possibly be in that area), but he can tell that she's teasing. So he adjusts his own tone as well, as his smile gets wider.

"You mean the floors I lived in three days ago? Yes ma'am, I think I know my way around."