In Ender's Game, Ender proved himself the greatest warrior in history by destroying the marauding alien buggers. Then he proved himself the greatest writer in history by taking the name "The Speaker for the Dead" and writing the story of the buggers's Hive Queen and making everyone sorry that Ender had killed the aliens in the first place. So now everybody thinks Ender is the world's greatest awesomest saintliest cool guy for writing about the buggers, and the most nefarious evil dude for killing all the buggers. But people don't realize super-awesome-dude Speaker for the Dead and xenocidal-evil-monster Ender are the same single impossibly awesome guy. That is irony.
So, two points: (1) Ender is fifteen times better than the best thing you can think of, and Orson Scott Card loves him, and if you don't love him too this book is going to be a long hard slog. (2) Ender is really sorry and guilty about killing lots of buggers, which makes him sympathetic and also somehow even more awesome than before.
You can read a complete Shmoopy summary of Ender's Game over thisaway if you'd like, but Ender = awesome = guilty should get you through the bulk of Speaker.
Oh right—and Ender has done lots of space travel speaking for the dead on different planets, and thanks to the tricks of relativity, that means that three thousand years have passed for most people even though Ender is still in his 30s. So he's basically lived forever. We said he was awesome, right?
On to Speaker for the Dead proper.
We start on Lusitania, a small human Catholic colony devoted to studying the piggies—or pequeninos—the first intelligent aliens discovered since Ender killed the buggers. The xenologists who study the piggies directly are Pipo, Libo, and a young, angry, alienated girl named Novinha whose parents died from a Lusitania virus known as the Descolada. Novinha's parents were the colony's xenobiologists, and they found a cure for the Descolada, but not in time to save themselves. Bummer for Novinha.
But the one bummer is not sufficient. Novinha grows close to Pipo and romantically involved with Libo. Then she tells Pipo something and he figures out something about the mysterious piggies and runs off to talk to the piggies about it; the piggies torture and kill him, and nobody knows why. Novinha decides no one can ever know what she found, so she locks it away in her files. But, if Libo marries her, as her husband he'll have access to her files because apparently in the future married people aren't allowed to have privacy. Anyway, because of stupid laws or poor plotting, Novinha can't marry Libo. Like Shmoop said before, bummer.
Novinha puts an interstellar space call out for a Speaker for the Dead to tell the story of Pipo's life. Ender on the planet Trondheim, city of Reykjavik, decides to respond because he wants to help the piggies and also because he falls in love with Novinha, who is thirteen… which is maybe a little icky, Card? But it's okay because the space flight will take just a few weeks for Ender but twenty-two years for Novinha, so they'll be marrying age when they get together. Thanks, relativity.
Ender leaves his sister Valentine behind, who has been his constant companion but has recently gotten married and become pregnant. Along with him Ender brings the Hive Queen—the last remaining bugger—who Ender carries with him in the hopes of finding a planet where she can restart her race. He also is constantly accompanied by Jane, an artificial computer intelligence who spontaneously generated in space and gives Ender super computer powers to go along with the rest of his general awesomeness.
When Ender gets to Lusitania, Novinha has canceled her call. But one of her children, Ela, called for a Speaker to speak the death of their father, Marcos Ribeira, or Marcao, who died of natural causes shortly before Ender's spaceship pulls up. In addition, another of Novinha's children, Miro, called for a Speaker four years earlier, when Libo was gutted by the piggies in the same way as his dad.
Ender gains the trust and love of Novinha's troubled children almost instantly because he is that awesome. He speaks Marcao's death, and reveals Novinha's secret, which is that she always loved Libo and married Marcao because she knew he had a disease which rendered him sterile, so all her children would be Libo's. Ender says Marcao beat Novinha because she did not love him, and that she wanted to be beaten because she felt guilty. People are upset at first (as you can imagine) but mostly they decide that truth is good and Ender is awesome, so all is well.
One of the folks who isn't quite convinced that truth is good is Miro, Novinha's daughter and one of the xenologists. Miro is in love with Ouanda, the other xenologist and Libo's daughter. But thanks to Ender, everyone now knows that Miro is Libo's son too, which means Miro and Ouando are siblings, which means that the religious Ouanda is absolutely not going to marry Miro. It is not that kind of book.
So, before Miro and Ouanda realized that they were brother and sister, they were happy xenologists together working with head xenologist (and their dad) Libo. These happy xenologists had all decided to defy Starways Congress and its Prime Directive, which said no interference with the piggies. (Okay, so it isn't called the Prime Directive. That's from Star Trek. And of course Card didn't steal Starways Congress from the Starfleet Federation. Of course not.)
Where were we?
So the xenologists decided to help the piggies out with technology and stuff. But Jane figures that if the colony comes under attack, everyone will accept Ender, and he'll be able to let the Hive Queen free on the planet. So Jane rats out Miro and Ouanda to Starways, and the authorities demand that Miro and Ouanda be shipped off-world for trial and take over the colony's computers.
Just as Jane suspected, everyone bands together in the face of Starway's shenanigans, and Ender is able to go meet with the piggies. Not part of Jane's plan is the fact that Miro ends up electrocuting himself on the fence in an effort to get to the piggies and help them out. He suffers permanent brain damage, but no one seems to remember or care that this is Jane's fault. In fact, after Ender and Jane have a tiff, Jane and Miro become best friends. The technical term for this is "plothole."
Ender meets with the piggies, and they sign a treaty saying that humans and piggies will help each other, and that Ender will let the Hive Queen free on the world where she can create a new hive. The piggies want to form an alliance with the Hive Queen, and their elders have been speaking with her mentally ever since she arrived on the planet. These elders are trees, by the way. The xenologists thought the trees were just trees (a natural enough assumption), but in fact they are transformed piggies. The piggies killed Pipo and Libo in an effort to transform them into trees, which is a great honor for piggies and marks the move to their next stage of life. The piggies are distraught to realize they killed the xenologists they intended to honor. Ender agrees to "kill" a piggie called Human who organized the treaty, turning him into a tree.
Almost done now, but jeez, lots of loose ends. The Lusitania colony is now in rebellion against Starways, and Starways is sending a ship out to them to kick their butts and take their names. In the meantime, Ender's sister Valentine—who is a famous political writer under the name of Demosthenes—has started stirring up public opinion in favor of Lusitania. She is getting on a ship and planning to come to Lusitania (the flight will take her thirty years). Oh, and also everyone realizes that the Descalada virus means that no one can be taken off Lusitania; the virus will infect every living animal, making it try to turn itself into a plant, which doesn't work out well. So evacuating the planet is not an option—which means Starways may well just be planning to destroy the whole honking planet. Which is a cliffhanger of sorts, though Starways's ship can't get to the planet for decades, so there'll be a lot of time to think about it/hang over the cliff.
Miro, now crippled, heads out with Jane to meet Valentine's ship; Ender and Novinha marry; and the Hive Queen is placed on the planet where she can start her brood. The end… until the sequel that is, in which Starways will do bad things, the piggies and the buggers and the humans all band together, and Ender will be awesome.