Natural Enemies, First Contact:2081

What if ancient alien astronauts really did visit Earth thousands of years ago? And what if the first alien race we enounter in space turns out to be an old natural enemy from our prehistoric past? An enemy which preyed on humans, and humans in turn attacked on sight?

The crew of the converted Star-Guardian "Ambassador" consists of experts in all areas of human knowledge. They train day and night to be prepared for the first human-alien contact. All scenarios that can be imagined by the human mind have been modeled by their powerful computer simulators.
What they never could imagine was first contact would be with an old, natural enemy from our prehistoric past. A fierce enemy which preyed on humans, and humans in turn attacked on sight.