In the spring of 1588 the Great Armada is ready to invade England. Europe remains in suspense before the master plan of Felipe II. A powerful fleet prepares to set sail from Lisbon, collect the Tercios in Flanders, cross the English Channel, land on the English coast and conquer the Protestant kingdom. Although the campaign is presumed quick, in El Escorial a parallel plan is meticulously organized that should help the success of the company. By order of Felipe II, a brotherhood of Cartagena is entrusted with a secret mission: to go to Lisbon to join the Great Navy, sail to Ireland, take up Irish Catholics and expel the English soldiers from the island. The confreres face the adventure with the conviction that they will make history, but, during the journey, certain sudden and mysterious deaths occur. The fate of the one known since then as the Invincible Armada and that of the confreres will be united. It only remains to know if it will be fatal for everyone.