Jan Haseck is a former Czech assassin who tried to kill Michael Westen several times shortly after he got burned
Jan is spotted by Michael in a bar and is greeted with a "Welcome to Miami asshole" in his native language. After two other attempts on Michael's life, Michael used his deathly allergic reaction to peanuts to force him answer his questions about his burn notice. Jan only knew that a lot of powerful and angry people were being forced to keep Michael alive. After the last encounter Michael injected the epi pen and tied him to the bench, getting Sam Axe to call the Feds. The naxt day Michael learns that Jan was taken from federal custody by people a lot higher up, then was found hanging by his shoelaces. Michael and Sam suspect that Jan was murdered, especially when Michael finds a plant and a smiley-face balloon delved to his doorstep, with a note telling him to: "Take care of that shoulder and we'll be in touch soon", signed "Your Old Friends".