Time Travel and Killer Robots

Fred Saberhagen created the Berserkers in the early 1960s, writing numerous short stories and novels featuring these robotic killers over the next few decades. The idea behind the Berserkers is this: Many thousands of years ago, self-replicating robots with advanced A.I. were built by an alien race to destroy an enemy. The Berserkers proved to be too efficient. Programmed to annihilate all biological life, it wiped out both races and then set out to destroy any other life it might run across.

It's a much-imitated idea--used, for instance, in the Star Trek episode "The Doomsday Machine."

The Berserkers are often in the form of asteroid-sized ships, but can build new Berserkers in all shapes and sizes as they adapt new tactics to changing situations.

Saberhagen's stories span across centuries of warfare between humanity and the Berserkers, with many of the stories focusing on human ingenuity giving us victory over the implacable killing machines. This often allows for some absolutely wonderful twist endings, such as those found in the short stories "The Peacemaker" and "The Annihilation of Angkor Apeiron."

The 1967 novel Brother Assassin (which first appeared in Galaxy Science Fiction magazine) introduces a fun new twist into the series. The novel takes place on the only planet in the galaxy on which time travel is possible. The planet Sirgol is surrounded by holes in space-time. When the first human ship landed on Sirgol, it was tossed back in time tens of thousands of years, with the warping effect wiping the memories of the crew. Civilization on Sirgol had to literally start from scratch.

When the next human ship arrives at Sirgol ten relative years after the first, they discover a thriving human civilization that's been around for 20 millennia who can warn the newcomers about the space-time holes. The planet is warned about the Berserkers in time to build a defense.

So when the Berserkers do arrive, they manage to wipe out "only" about 90% of Sirgol's population. The survivors take refuge underground. The inhuman enemy then tries using time travel to disrupt the flow of civilization and change history. If they succeed, the humans on Sirgol won't be advanced enough to fight back at all when the robots first arrive.

What follows are three separate adventures, linked together by the same human characters. The Berserkers try to wipe out a tribe of humans who would be the first to develop a written language. Humans from the present can't travel back that far without losing their memories, so they send back robots worked by remote control to act as bodyguards to the tribe.

After that, we discover that history on Sirgol roughly parallels that of Earth, with the rise and fall of a Roman Empire analogue. The Berserkers try to change history by killing a king who keeps one nation from descending into a Dark Age after the Empire falls. (The king is an analogue to King Arthur--Saberhagen borrows Sirgol's history from Earth legend as well as fact.) This time around, countering the Berserkers move means to somehow replace the dead king--at least until the duplicate can draw a Berserker dragon out of hiding.

Then, the robots try more subtle means of changing history, mucking around with the results of the trial of a Galileo analogue during Sirgol's Renaissance. Here, the book's protagonist must use an equally subtle plan to get history back on the right track.

It's great storytelling, with strong characterizations backing up the clever plot. Also, there's some thoughtful thematic subtext present. For instance, the King Arthur section deals with self-sacrifice and heroism with enough real emotion to keep it from seeing cliched. The Galileo section deals with the apparent conflict between science and faith, but in the end reminds us that both are necessary and valuable parts of human history. I have no idea what Saberhagen's personal beliefs are, but one of the reasons I enjoy his stories is that he occasionally acknowledges and celebrates the vital influence Judeo-Christian values have had on civilization.