End of the 20th century. A group of scientists executes a project aiming to prevent a nuclear war with the planet Khalom. From their experimental project, involving manipulating events in the past, two mysterious human creatures travel between the present and the 19th century, and back - getting in love with four different persons.

In Portugal, in the 60s, the corpse of a man appears on Dog's Beach. The corpse is identified as the major Dantas, a man wanted by authorities after his escape from a military prison where he was awaiting trial for insurrection.