The tunnel Danny katz series, book 2.

Once a promising military intelligence officer and high-functioning heroin addict, Danny Katz now uses his gifts as a linguist and computer programmer in his work as a private investigator. His drug habit ultimately derailed his earlier career, but now he is clean-and self-employed. In short, Katz is used to his fair share of suffering and all too familiar with Stockholm's seedy underbelly. When his former drug dealer, Ramón, dies from an app...