The forbidden door

Once a happily married top agent with the FBI, Jane Hawl is now a widow wanted by the agency she once worked in. Hunting her enemies comes with its own costs, and now those she seeks revenge against are prepared to fight back, using her five-year-old son as bait. But an increasing number of people are becoming afflicted with a mysterious brain-altering malady that drives them violently insane, leaving everyone's lives in danger.