L'ultimatum di Natale

If an alien secretly escapes from a base at Altrove, where he was staying as a guest in utmost secrecy, it’s a big problem. If he then dies mysteriously when Tower’s men try to convince him to return, the problem gets even bigger. When the aliens from his planet don’t believe it was an accident and threaten to destroy Earth in retaliation, the problem becomes so severe that Chris Tower has no choice but to ask for Martin Mystère’s help. And so the Detective of the Impossible is left with only hours to solve the case and prevent the extinction of the human race…

The issue also includes a story of Zio Boris, the column I Mille Mondi di Alfredo Castelli and the Docteur Mystère strips!