At the end of season five, Sue Dearbon’s case came across Ralph’s desk. He left to search for the girl and returned with nothing. Sue’s parents hired him and he got as far as Opal City before returning to Central City. Comic readers know that Sue eventually becomes Ralph’s wive and partner.
The Flash show runner warn viewers that Sue will come with a twist. “We have to solve the mystery of where is Sue exactly, what’s she doing, and more importantly, why? It’s a season-long mystery that is going to take a twist in the back half. And when we finally do meet Sue, she might not be the woman that Ralph is expecting.”
Here’s the official character description, courtesy of tvline.com: “Possessing a fierce intelligence and a spitfire personality, Sue Dearbon is the daughter to one of Central City’s most wealthy families. But there’s much more to Sue than just the socialite reputation that always precedes her, which master detective Ralph Dibny will discover when they finally meet later this season.
The Flash airs on Tuesday nights on The CW.