Casting continues for the second half of The Flash‘s freshman season, introducing two siblings of existing characters.

The Flash is going to be a family affair in 2015. Our first casting announcement is that of Peyton List (The Tomorrow People) as Lisa Snart, sister of Leonard Snart, aka Captain Cold.

The official description of Lisa’s character reads:

“While Leonard is cold and calculating, Lisa is a wild child and anxious to prove to her older brother she’s got what it takes to be in his criminal gang. She is sly, charming, and even a little sadistic. She’s also not afraid to use her sexuality to get what she wants, which will put her on a collision course with S.T.A.R. Labs employee and friend of The Flash — Cisco Ramon (Carlos Valdes).”

In the comics, Lisa is a supervillain known as Golden Glider; as a former ice skater, she, like her brother, uses ice-themed attacks against The Flash.

She is expected to debut in The Flash season 1, episode 16, “Rogue Time,” according to Access Hollywood.

In addition to Lisa, we’ll also be meeting Cisco’s brother, Dante, reports TVLine. Sleepy Hollow alum Nicholas Gonzalez will play the gifted pianist “who never reached his potential and secretly resents Cisco’s success.” Of course, in Central City the brothers will be “thrust into extreme circumstances,” and “Dante must rely on Cisco if they’re going to survive.”

Dante made his DC comics debut in April 2013’s Justice League of America’s Vibe #1, so he’s a relatively new character.

He will also appear in The Flash season 1, episode 16, “Rogue Time.”

The Flash returns with new episodes on Tuesday, January 20 at 8:00 p.m. ET on The CW.