Kisa the Little Devil
When the first contact was made weeks ago, Nikolai was directly notified by his underlying. In turn, he went and informed her good sister, Kisa. She was known for her critical thinking and knowing that Maxim was dead for years now, Nikolai seemed to have a hunch that someone had gotten their hands on Maxim's information and contacted them.
That's what Kisa also thought and asked her brother to personally see the matter through to the end.
It was just that she had a busy schedule with her friend Maria and couldn't abandon her, or else she would have gone to the meeting herself.
All she asked from her brother was to confirm if it's their long dead Maxim or someone else. If it was the former, she emphasized that he must be careful as if Maxim was alive, then he wouldn't be the same Maxim they knew. And if it was the latter, he should exterminate everyone around him and forget about the matter.