Off of her best friends' advice, Calysta applied to work for the BAU. Previously working with Emily Prentiss (the best friend) at Interpol, she was fascinated with the stories and logic that Emily said. She was a "tough cookie" as Emily told her, a little "rough around the edges" but she was incredibly brilliant and a good team player and leader. Beautiful but deadly, Interpol people seemed to call her. And Hotch needed to catch his breath when he saw her. Little did he know she felt the same...