Everyone knows someone who has died. In the circles of Estonian friends who use "china white", death is a constant possibility. They know that. But that does not mean they can stop.
It's so addictive," says Marko, who has lost two friends to overdoses, and survived two himself. In Estonia, the drug - whose proper name is Fentanyl - is taking a heavy toll of young people. Nationally, drug overdoses now kill more people than road accidents.
Marko desperately wants to break his addiction. He started injecting seven years ago, aged 18.
I was young and stupid. I tried it with my friends when I was drunk and began to like it, and soon I was doing it every day," he says. He has managed to cut down, and is currently shooting up three or four times a month. But he needs a daily dose of methadone to cope with the withdrawal symptoms.
And the mental dependence is much harder to deal with.