This is in Nikita S4 which Alex keeps on taking without supervision. Who do you think is the mole also :))
Sobelex is a made-up name for a narcotic or opiate pain killer. It doesn’t exist in the real world, but I’m not sure why they didn’t just use the name of a real one. Before she took it she winced and referred to her arm where she had been shot. A few episodes back Birkhoff offered some to her after she was shot and she declined because she was a forced addict before she was rescued by Nikita. I’m guessing her situation with Sean is making it harder for her to cope with the pain so she’s backsliding. Notice she took one right after he left Division and right after she called and he didn’t answer.
As for the mole, I think it’s Sonya. She was the main techie when Amanda was in charge at Division and she’s suddenly interested in having dinner with Birkhoff while he’s working on that new project. He looked at her suspiciously as well. I can’t think of any other main character that it could be.
It kills pain but it doesn t really it s just acting like it does.
Woah! Give a spoiler alert! WTF