Since Dr. Charlotte Cross, from the CDC (Centers for Disease Control), just showed up in town looking for him, Dave decides to get in front of the problem by enlisting the aid of Chris Brody, a local marine biologist who has a "charm" Trouble. Remember him from Season 2? We're sure Audrey does… *wink*
By using his Trouble, Chris is able to convince Dr. Cross that the mysterious inter-dimensional scar on Dave's leg is nothing more than a jellyfish sting. With that problem solved, Dr. Cross makes ready to enjoy her time in Haven as a tourist rather than a health care professional. Unfortunately, during a romantic dinner with Dwight, someone falls to the ground with a nasty infection that Dr. Cross insists on helping with. As if that wasn't enough of a problem, dancing bears start popping up all over Haven. They seem harmless until they take off their masks and reveal an empty shell where a head should be. It's only a matter of time before Dr. Cross sees one.
It doesn't take long for Audrey and Nathan to track the dancing bear Trouble down to Eve, a woman who lost her father ages ago in a tragic accident. Audrey tries to talk her out of the Trouble but it doesn't work and, worse, more and more people around town keep getting sick. The sickness seems to be triggered by fear and only affects Haven residents who also have Troubles. Even worse, the disease is causing people's Troubles to be activated.
Before long, Dwight makes the tough decision to hide all the infected/Troubled people in the hospital into a single ward. This doesn't work so well, especially when Dr. Cross discovers all the sick patients there. She thinks that Dwight and the other Haven residents are covering up foul play and she decides to call in the rest of the CDC to quarantine the city. They are able to stop her call by destroying the local cell phones tower but they can't contain her for long.
Meanwhile, back on Duke's boat, Mara has poisoned the well and convinced Duke to side with her against everyone else. Uh-oh…