Four extraterrestrials, X-1, X-2, X-3 and X-4, arrive on Earth in the early sixties. Here they decide to take on human features to study the terrestrials incognito, but end up getting involved in the Roman "dolce vita".
Paolo Panelli
X1
Carlo Croccolo
X4
Enzo Garinei
X3
Alfredo Landa
X2
Magali Noël
Matilde Bernabei
Ciccio Ingrassia
Lo scrittore di fantascienza
Franco Franchi
Socio dello scrittore
Pietro De Vico
Cameriere d'Hotel
