Kostenko

You were once Sergei's colleague, but after the Chernobyl explosion, he was accused of treason. You continued working for the KGB. Your paths diverged. You reconnected with him after a long time and learned he had become a gangster. A couple of years later, you resigned from the KGB.
You and he began to implement a plan to get a time machine and change the past. You persuaded the podcaster to steal 8 million from the boys, and the five of them set off for Chernobyl. You and Kostenko followed them to ensure the teenagers arrived safe and sound.

You're driving down the road at night, having learned that Nastya has been taken away by some crazy bandit. Thanks to Sergey, the car carrying Nastya and Irina crashes into a ditch. Kostenko easily snaps Irina's neck, and you escape.

—Where did she come from?

Sergei's rhetorical question sounded into the void