Release Message:  The Doctor (Peter Davison) figures that the Urbankans have visited Earth several times over thousands of years, with each visit coming closer together, but this time the Urbankans have come to stay.

Description:  The doctor figures that the Urbankans have visited Earth several times over thousands of years, with each visit coming closer together, but this time the Urbankans have come to stay. Bigone reveals how he and the other cultural representatives, taken at each visit, have lived so long.