The Heechee are a powerfully advanced elder race that featured in works of Frederik Pohl]].
The Heechee existed more than 500,000 years earlier where they were active in their explorations of the galaxy and were known to had come to the planet Earth when Australopithecine inhabited the world. In this time, they were known to had taken a sampling of these creatures that were extracted that were allowed to later propagate on a Heechee station. During their early history, they discovered a race of pure energy beings known as The Foe that had wiped out any civilization on worlds where they emerged. Heechee evidenece indicated that the Foe intendd to add matter into the universe in order to bring about the collapse of the universe. Thus, the inherently cautious Heechee decided to retreat to the interior of a black hole in the Galactic Core where they hoped to avoid being destroyed. It was the time dilation effects of the black hole that led to a few hundred years passing whilst within the interior of the black hole. After emerging from hiding, the Heechee scout vessels were periodically sent outside the black hole in order to determine the developments occuring throughout the universe in general but also keeping a particular watch on the emergences on Earth. This was because they intended Humans to discover their ships and that mankind would slowly study them in order to unlock their secrets over a period of hundreds of years.
After one Heechee crew existed the black hole, they were shocked to discover that Humans were flying their vessels to all parts of the galaxy. One of these places was also the Kugelblitz that was a black hole made of energy and was where the Foe resided. The cautious Heechee were thus shocked to see Humans utilizing their ships in a manner that they had not expected which was taking them to random locations in the dangerous galaxy. When the Heechee arrived in force, they had decided that the Human intrusions was not capable of being reversed and that the Foe needed to be confronted.