“NCIS: Los Angeles” Season 10, episode 21 will focus on a prison break. The promo videos of the episode show that Anastasia “Anna” Kolcheck will be back. She will escape from a correctional facility, and Callan (Chris O’Donnell) will have to help track her down before she is murdered.

A promo video of the next episode shows Callan and Sam (LL Cool J) visiting the correctional facility in order to find out why and how the prison break happened. The former agent Anna will escape along with her cellmate for some reason, and the preview video shows her life will be in danger after the escape.

“We need to find her before she’s killed,” Callan says in the preview.

A sneak peek scene from the next episode shows Callan and Sam casually chatting about how Sam’s acquaintance from the time he was undercover as an arms dealer. While Callan teases his friend about a lady who was very keen on reconnecting, a U.S. Marshall approaches them about Anna’s case.

The U.S. Marshall takes Callan in to help with the case, and Sam follows them in his car. The team will get involved to help solve the case quickly.

It isn’t clear why Anna will escape from the correctional facility and what her cell mate has got to do with it. However, the promo video shows someone pointing a gun at her head while she kneels.

Four more episodes are left in the current season. While Season 10 is coming to an end there is good news for the fans. The producers announced on Twitter that the show has been renewed for Season 11.

“NCIS: Los Angeles” Season 10, episode 21 is titled “The One That Got Away.” The episode will air on April 28 at 9 p.m. EDT on CBS Television Network.