Emotions are highly contagious among humans. How are they transmitted? Which emotions are the most contagious, and what are their positive and negative effects on us? Can we disinfect ourselves from destructive emotions? Are we emotionally toxic or beneficial to those around we? To answer these questions, Christophe Haag takes us on a fascinating journey: on board a spaceship, inside the pervasive confines of a sect, on hair-raising mountain expeditions, and into the nerve-wracking "negotiation" cell of a police anti-terrorist unit...