A romance written by Creator/CarlSagan, it tells the story of our first contact with extraterrestrial intelligence... but in a manner much more realistic than the usual portrayal with [=UFOs=] and impossibly quick interstellar travel.

Ellie Arroway, a radioastronomer working in Socorro, New Mexico, discovers a steady and clear signal coming from a point in space that corresponds to the distant star Vega. The signal is confirmed to be legitimate, and soon a worldwide effort is made to receive the message whole(due to the impossibility of monitoring the same spot in the sky as the Earth revolves) and then to decipher it, while religious and political uproar rises all around.

Was adapted into a [[{{Film/Contact}} film]] in 1997. Not to be confused with the unrelated game ''{{VideoGame/Contact}}'' or the trope FirstContact, although the plot centers around the latter.

!!This novel provides examples of:

* AliensSpeakingEnglish: Averted, at least in the most common sense. The idea that a different civilization, with different history and technological level, would be transmitting in binary in the same fashion as we do, though, is a very close call.
* AliensStealCable: The first signal sent to us is a repetition of the first of Earth's radio transmissions to reach space (which was what alerted them of our presence): Adolf Hitler at the overture of the Berlin Olympics. Fortunately, it's only used as a vessel for a coded message.
* AlternativeNumberSystem: Apparently someone [[spoiler:capable of messing with the values of mathematical constants]] likes base 11.
* ArcWords: Each chapter is named after a concept that's important to the events described in the chapter. Maybe the most important: "palimpsest" (a message written under another message in a roll of parchment).
* {{Epigraph}}: Every chapter.
* FasterThanLightTravel: An actually plausible version of this, at that.
* FirstContact: Aborted realistically. There are no little green men coming in impossibly quick metallic ships, but a radio signal just like the ones we do send into space as well.
* FirstContactMath: The reason the signal is considered a signal of intelligence is because it transmits a long series of prime numbers. As it turns out, it was only a way to attract our attention, as the message is hidden underneath it (and the really important message is hidden underneath the original message).
** They also use prime numbers to codify images and video (each number codifies the coordinates of a black point as a product of primes).
* AFormYouAreComfortableWith: Near the end of the novel, [[spoiler: the humans are greeted by aliens who look like familiar humans in order to make the experience less frightening. Ellie sees her late father.]]
* TheGreatPoliticsMessUp: The USSR is still around in the book's version of 1999, although a more united humanity has put the UsefulNotes/ColdWar on hold.
* HeroicBastard: [[spoiler:Ellie, the protagonist,]] finds out in the very last chapter that [[spoiler:her deceased father, whom she idolized, is not her father. Her (not actually "step-") stepfather, who she despises, [[GlorifiedSpermDonor is]]. This shocks her ''more'' than the message from God (?) inside Pi]]. This subplot is completely absent from [[{{Film/Contact}} The Movie]].
* HigherTechSpecies: The FirstContact aliens.
* PortalNetwork
* PrecisionFStrike: Ellie tends to say "Holy [[UnusualEuphemism Toledo!]]" when other people are around. After receiving the signal, she retreats briefly to her office, closes the door, and whispers "Holy shit!"
* {{Precursors}}: The unknown aliens ([[spoiler:or god(s)]]) who built the wormhole network.
* ReligionIsRight: A subtle variation of this trope occurs at the end of the novel. Ellie discovers [[spoiler: a "signature" of sorts of the creator of the Universe hidden inside Pi. At the ''same time'' she discovers the other thing mentioned above.]]
* SufficientlyAdvancedAlien: The FirstContact aliens, the Precursors, and [[spoiler: ''maybe'' the creator of the Universe.]] The journey is to an artificial world where the aliens are researching physical constants looking for messages written into reality itself -- ''[[ThatsNoMoon a church the size of a planet]]''. And once they return, the main character is able to find one of these messages herself. Thus, Sufficiently Advanced Science is indistinguishable from '''religion'''.
* TechnologyMarchesOn:
** At one point Ellie channel-surfs and finds a station offering onetime access to [[{{MMORPG}} a downloadable fantasy RPG game]]; if you liked it, you could order the full game ''on a floppy disk''.
** While leaving a museum with Palmer Joss, Ellie receives a message on her ''beeper''. She has to get back to her office because she can't find a ''pay phone.''
** The way space tech and travel is depicted didn't exactly play out in the real 1999.
* TwentyMinutesIntoTheFuture: The novel takes place during TheNineties...as seen from TheEighties.
* SciFiWritersHaveNoSenseOfScale: Naturally averted. He's a scientist, after all.