A man speaking a foreign language gets a call. He grabs a gun from a drawer in his hotel room before heading out. On the night streets of Philadelphia, a young girl kicks her way out of a car trunk. Her hands are bound. She's scared as she runs down an alley. BANG! BANG! Two bullets pierce her body. The girl collapses to the ground.
We jump back three hours earlier. Kate is making the rounds at a swanky international event. She rebuffs flirts from D.A. Dan Russell to do some flirting of her own with a handsome man named Sergei. The guy says he's attached to the Ukrainian attaché. Then he's attached to Kate as the two of them retire to his hotel room for a night of passionate love-making. Sergei gets a call. He grabs a gun from his dresser drawer. He's the person that was seen earlier. Sergei is seen standing in the alley where the young girl was shot. He stands over her body as she struggles to crawl away.
The young girl's body is found the next day. Megan determines she's been dead at least eight hours. Kate gets a text about the case. Duty calls. She gets dressed quickly while asking Sergei to zip her up. At the office, Megan sees that someone snatched a necklace off the victim. There's also a barcode on her neck suggesting she's a marked prostitute. Ethan finds a note written in Russian sewn inside the dead girl's dress. Kate calls Sergei in to translate. The note is to the girl's mother. The victim's name is Oksana. She was pregnant. Someone cut the baby out after she was shot.
The baby's father is Arco Starkovich, a Ukrainian-American who is big in the import-export business. Tommy and Megan catch him just before he was heading off to celebrate his mother's birthday. Arco claims he met Oksana at a place called Club Tatyana. Adam knows the owner. Tatyana takes an instant shine to Megan. She says the barcode on the victim's neck indicates she was victim of sex trafficking. Back at the office, Kate is shocked when she sees a photo from the political event. It shows Arco getting chummy with Sergei.
Sergei claims he only met Arco for a few minutes at the gala. Kate isn't sure what to believe when she finds a bloody shirt in the closet. She sneaks it into her bag before hastily leaving Sergei. She accidentally leaves her cell phone behind. Kate runs tests to determine that the blood came from the victim. Megan learns from Tatyana's girls that a man came in looking for girls with barcodes. She deduces that it was Sergei, who returns Kate's cell phone to her at the office. It's a tense situation, but Kate plays it cool. She convinces Sergei to let her meet him back at the hotel.
Sergei has been in the States for weeks looking for Oksana. He may be a multiple murderer as two other girls with barcodes are also missing. Tommy knows the only way to make the bloody shirt admissible is if they put it back and get a warrant. It's a dangerous situation, but Kate is up for the mission. She convinces Sergei to leave the room while she puts the shirt back where she found it. Unfortunately, the wire Kate is wearing is discovered. Sergei bolts. Tommy tracks him down at the airport. He arrests him, but questioning must cease when diplomatic immunity comes into play. Sergei tells Kate that he didn't mean to hurt her before walking free.
Kate notices that the necklace Oksana was wearing in all her photos was not on her body when they found her. That's because it was being worn by Arco's mom. This lady is the mastermind behind the sex trafficking operation. She was upset when she learned her son got Oksana pregnant. Mama killed the girl and wore her necklace as a warning to her son to not mess with her business.
Kate goes to the Ukrainian embassy to see Sergei deliver Oksana's baby to her parents. The girl had been kidnapped. Sergei was hired to save her, but she died in his arms. He managed to save the baby. He also rescued two other barcode girls. He couldn't say anything until the baby was safely delivered to Oksana's parents. He lets Kate know that the little girl is named after her. Then he says goodbye.