Beyond the Blue Event Horizon is a science fiction novel by the American writer Frederik Pohl, a sequel to his 1977 novel Gateway and the second book in the Heechee series. It was a finalist for two major annual awards, the 1981 Hugo Award for Best Novel and the 1980 Nebula Award. In the 1981 poll of Locus readers (Locus Award) it finished second to The Snow Queen by Joan Vinge.
The novel tells the story of Robin Broadhead, who, after he makes a fortune on his one successful trip in an advanced alien Heechee spaceship, lives very comfortably. He finances an expedition to a Heechee "food factory" in distant solar orbit, hoping that the family of four explorers can help the starving millions of Earth. He also hopes that they can unlock enough Heechee technology secrets to help him save his long lost lover Klara. The food factory expedition leads where no one expected--an ancient, gigantic space station, named Heechee Heaven, which changes the human understanding of the Heechee race forever.
Plot
Earth struggles with overpopulation and starvation, and even though humans have gained access to the mysterious Heechee technology, including their faster-than-light spaceships, this has not done much to mitigate these issues. A "food factory" spaceship, long abandoned by the Heechee, is found deep in the Oort cloud, and an expedition funded by Robin Broadhead, a millionaire former Gateway prospector, is sent to investigate. The crew, a family of four, is astonished to find a young man, Wan, occupying the spaceship. Wan tells how he grew up alone on Heechee Heaven, a faraway space station and of how he regularly visits the food factory for supplies and entertainment in his small Heechee spaceship. He is as ignorant about social cues as he is about the inner workings of Heechee technology. The youngest crew member, teenage Janine, is enamored with Wan, as he is the first young man she has seen since their four-year voyage started.
Wan shows Janine around the food factory, introducing her to the dreaming chamber. Wan's repeated usage of the dreaming chamber coincides with semiannual outbreaks of a mysterious planet-wide fever that has hit Earth regularly over the last decade, and the crew quickly realize that Wan's dreams and nightmares are somehow psychically projected at the population of Earth at lightspeed, causing the "130-day fever". Janine briefly tests the chamber herself before her father and brother-in-law dismantle it.
Meanwhile, status reports are streaming back to Earth at lightspeed, creating a 26-day lag in communications for Robin Broadhead. Wan's final use of the dreaming chamber causes accidents worldwide, including one which severely injures Robin's wife Essie; Robin's time becomes divided between worrying about his wife and worrying about his crew. Robin's motivations seem altruistic instead of financial--he genuinely hopes to use Heechee technology to feed the starving billions of Earth, but secretly he hopes to use the food factory to master Heechee technology such that he can rescue his lost love Klara, whom he stranded years before in a Heechee ship in a black hole at the conclusion of Gateway.
Wan leaves the food factory with Janine, her older sister Lurvey, and brother-in-law Paul in his Heechee spaceship, headed for Heechee Heaven. He tells the crew Heechee Heaven is home to Old Ones, who the crew assume are Heechee, and the "Dead Men", who seem to be self-aware computer recordings of the personalities of dead, human Gateway prospectors who can communicate with the food factory via FTL radio; the Dead Men are Wan's only friends. Due to space constraints they leave old Payter, the father of Janine and Lurvey, behind alone at the food factory. Robin Broadhead is excited and terrified about a physical encounter with the Heechee, even from so far away.