Farthest Star

Cuckoo was coming.

No one knew what is was - but everyone knew it was trouble.

Designated Object Lambda when it first appeared on the fringes of the galaxy, 20,000 light-years away, it was traveling at one-sixth the speed of light.

The astrophysicists said thet it was vast... light... and had the potential for utter destruction. So an exiting space probe was reoriented to intercept; it was staffed with replicates of both humans and aliens.

Then the space probe began to leak radiation...