Alex Rider Wiki

Estrov was the Russian town where Yassen Gregorovitch was born and grew up in. The town only appeared in spin-off novel Russian Roulette.

Russian Roulette

Due to a chemical accident in town, (caused by Vladimir Sharkovsky's carelessness and greed,) the then young Yassen had to escape to a nearby town before he was hunted by the Russian government, who wanted the accident to be known by nobody, especially after the Chernobyl accident.

All of Yassen's family members died in the accident, as well as his best friend.