'Supergirl': "Blood Memory" Preview Released

The CW has released a promo for "Blood Memory", the upcoming eleventh episode of Supergirl's fourth season and in it, Alex's sacrifice to protect Supergirl's identity appear to have some serious consequences.

In the promo, which you can check out above, Alex isn't just missing knowledge that Kara is Supergirl, but potentially a lot more and it's creating real issues both for her cognitive abilities and perhaps even her sense of self.

Unfortunately, the mind wipe was necessary. In Sunday night's midseason premiere, Colonel Haley was able to discover Supergirl's civilian identity after interrogating DEO agents. Armed with this information she planned to force Supergirl into service -- not a good thing considering that Haley is definitely in the anti-alien camp. Before this could happen, though, Alex knocked Haley out and J'onn wiped her mind of Supergirl's identity. The wipe didn't remove Haley's desire to find it out, though, prompting her to enlist a truth-seeking alien creature. The only course to protect Supergirl, then, was to wipe the minds of all agents with the knowledge -- including Alex.

While Alex's memory issues will be an issue in the episode, it isn't the only thing that Supergirl will have on her plate. Still photos form the episode show Kara joining Nia Nal on a visit to her family where Nia will get some encouragement from her mother.

Last November, it was reported that Outlander alum Hannah James and Scandal and Grey's Anatomy alum Kate Burton had been cast as Nia's (Nicole Maines) sister Maeve and mother Isabel respectively.

Maeve Nal is described as being a driven young woman focused on maintaining her family's rich legacy and while she's always had to work a little harder for her achievements than Nia, the sisters are described as having a very strong bond. As for their mother, Isabel, she is described as being a local hero in her own right who raised her family "to be bold and courageous, as well as to love fiercely and openly."

The episode may also contain the beginnings of Nia's transition into Dreamer -- complete with super suit. Maines told reporters during a visit to Supergirl's set that she's very excited for her character to suit up.

"I'm so excited," Maines said. "I'm trying to conduct myself on set in a professional manner and be like 'I'm not completely obsessed with the super-suit,' but it's all I think about. Every morning I wake up, 'I'm getting a super-suit!' I'm going to sleep, 'I'm getting a super-suit!' I'm really, really excited. It's gonna be gorgeous! I have the best super-suit. I do."

You can check out the synopsis to "Blood Memory" below.

KATE BURTON GUEST STARS; NIA AND KARA VISIT NIA'S HOMETOWN -- Kara (Melissa Benoist) joins Nia (Nicole Maines) on a trip to Nia's hometown to visit her family during the town's annual Harvest Festival. While home, Nia's mother (guest star Kate Burton) encourages her daughter to embrace her destiny. Meanwhile, Alex (Chyler Leigh) deals with a street drug that is turning people violent and giving them temporary superpowers. Shannon Kohli directed the episode written by Jessica Queller & Dana Horgan.

Supergirl airs Sundays at 8 p.m. ET on The CW. "Blood Memory" will debut on January 27.