On November 13, 2015, ten months after the attacks on Charlie Hebdo and the Hyper Cacher at the Porte de Vincennes, three jihadist commandos, divided between the Stade de France, the Bataclan and the terraces of the 10th and 11th districts of Paris, spread death in the capital. How were these men, mostly French and Belgian, some of them actively sought, able to cross Europe and carry out their plans without being worried? Faced with the loopholes revealed by the attacks, fourteen European countries, supported by Europol and Eurojust, the EU's police and judicial cooperation agencies, pooled information and resources on an unprecedented scale to identify and track down the culprits, accomplices and sponsors of these attacks.