This Christmas we commemorate the thirtieth anniversary of the Beagle Channel crisis. This contributíon reconstructs this piece of history, from its beginning in 1977 to the menace of war, the Vatican mediation and finally the ratification of the Treaty of Peace and Friendship by Argentina in 1984. Dismissing simplistic analogies with the Falklands war, the reduction of the crisis to a populist manoeuvre of the Argentine Military Junta is refuted and the hypothesis of a bluff called by Chile with the support of the Vatican is proposed. The treaty is approached intertwining the mediation's dynamics with the broader context of the Argentine transition and the economic conjuncture. This reconstruction is based on puhlished material as well as on hitherto unpublished interviews.