Actress Jewel Staite has joined the cast and will play the role of Rachel Turner who is tech genius/roboticist from the future, it's being said that she is a descendant from a long line of inventors from DC universe my guess would be Ray Palmer but you never know it could be someone else.
Pilot Part 2 Description:
STEIN VS. STEIN — Tipped off to Vandal Savage’s (guest star Casper Crump) whereabouts, the team infiltrates a munitions deal with Professor Stein (Victor Garber) as their leader. Surrounded by some of the toughest criminals in the world, things quickly go from bad to worse when Savage realizes they don’t belong there. A massive fight ensues and a piece of the Atom’s (Brandon Routh) suit falls off and into the wrong hands, which could potentially cause disastrous consequences in the future. Stein realizes the best way to retrieve the missing piece is to contact a brilliant man – his younger self. He, Sara (Caity Lotz) and Jax (Franz Drameh) head off in search of young Martin Stein (guest star Graeme McComb), much to Rip’s (Arthur Darvill) consternation. Meanwhile, Snart (Wentworth Miller) and Rory (Dominic Purcell) plan to steal a key element in defeating Savage but still unsure of his new teammates, Ray (Brandon Routh) demands to come along on the mission. Carter (guest star Falk Hentschel) helps Kendra (Ciara Renée) remember something vital.
The producers of the show have said there's a 100% chance we'll see either younger or older versions of Oliver Queen and Barry Allen in the show.
Jonah Hex will be appearing in show but no one has been cast for the role yet.