After finishing Episode 1 of 3 Body Problem, you might be asking yourself: “Did the stars really just wink at the human race?” Don’t worry, you’re not alone. You, like every scientist in the series, are simply trying to grapple with the universe’s deepest mysteries.

Based on the bestselling novels by Cixin Liu, the new sci-fi drama series from Game of Thrones creators David Benioff and D.B. Weiss, and True Blood writer/executive producer Alexander Woo, explores humanity’s response to its greatest threat: other beings coming to conquer the planet. Over the series’ eight episodes, each character decides how they wish to be remembered in the fight for humanity. 

The series begins during China’s Cultural Revolution in the ’60s, introducing a young woman who will go on to make a fateful decision that reverberates across space and time into the present day. When the laws of nature inexplicably unravel, a tight-knit group of brilliant scientists must join forces with an unflinching detective and a mysterious intelligence agency to save the world.

Because the series jumps back and forth through the years, we’ve created a chronological timeline to help you keep track of every key event in 3 Body Problem, from the ’60s to 400 years from now. (If you need help with the science, head here.)

What happens in ’60s China in 3 Body Problem?

The series kicks off at Beijing’s Tsinghua University in 1966, where astrophysics prodigy Ye Wenjie (Zine Tseng) watches a struggle session (aimed to break and humiliate people accused of being “class enemies”) in horror. With the principles of science under attack, the Chinese Cultural Revolution’s militant youth group, the Red Guards, violently murder physics professor and Ye Wenjie’s father, Ye Zhetai (Perry Yung). 

Her life forever changed, Ye Wenjie finds herself in a labor camp in Inner Mongolia, China, in 1967. Reading environmentalist Rachel Carson’s Silent Spring (1962) at the urging of a fellow laborer turned lover, she learns that “in nature, nothing exists alone.” Condemned for possessing the book, she’s offered the choice to rehabilitate at a top secret military base or go to prison. Not hard to guess which life sentence she chooses. Soon, she learns the true nature of the Red Coast Base and why they have a giant satellite dish on top of the hill: They’re trying to communicate “with whomever is out there.” 

In 1968, Ye Wenjie figures out that they should be using the sun as a super-antenna, so she turns the satellite dish to face the sun even though her superior forbids it. At that point, they’d been broadcasting the same message to otherworldly beings for a few years to no avail: “We extend our best wishes to you, inhabitants of another world. We hope to establish contact with other civilized societies. We look forward to working with you to build a better life in this vast universe.”

What happens in 1977 in 3 Body Problem?

In 1977, Ye Wenjie meets the young, like-minded environmentalist Mike Evans (Ben Schnetzer) in Shaanxi, China. He’s trying to save an endangered bird, but the government wants him to move off their property. Ye Wenjie also encounters Tang Hongjing (Lan Xiya), the Red Guard who killed her father, Ye Zhetai. Ye Wenjie’s faith in humanity continues to falter, as Tang Hongjing has no desire to repent for her brutality.

Later that year on Aug. 15, 1977, Ye Wenjie receives a message back from the San-Ti (so-called because Sān tǐ-rén means “three-body people” in Chinese, and she first made contact with them in China). The responder warns her not to answer, because if the San-Ti come, they will conquer her world. She answers anyway, making a fateful choice on behalf of humanity: “Come. We cannot save ourselves. I will help you conquer this world.” Light-years away, the San-Ti begin to plan their trip to Earth.

Ed Miller

What happens in the early ’80s in 3 Body Problem?

In 1982, Ye Wenjie is now a professor at Tsinghua University. She meets with Mike Evans while she’s in London for a conference.  He’s still passionate about the environment but now with a lot more means — he’s become a billionaire after inheriting his father’s oil company, Evans Energy. Ye Wenjie confides in him about reaching out to the San-Ti.

In 1984, Evans brings Ye Wenjie to Judgment Day, an oil tanker in the North Atlantic Ocean. Without any political orders or interference, he’s converted it into their own signal base to contact the San-Ti. He tells her that the San-Ti have tried to contact her since receiving her 1977 message and that she’s very important to them. Ye Wenjie and Evans kiss. Their daughter, Vera Ye (Vedette Lim), is born in the UK that year.

What happens in the late ’80s to early 2000s in 3 Body Problem?

Ye Wenjie moves to England, while Mike Evans continues to send communications to the San-Ti on Judgment Day. 

Together, Ye Wenjie and Mike Evans create an organization designed to best prepare the San-Ti for their arrival. The movement worships the San-Ti, whom they call “our Lord.” Many San-Ti followers come to live on Judgment Day.

Ed Miller

What happens in 2016 in 3 Body Problem?

Vera Ye is an expert in particle physics and a professor at the University of Oxford. Five of her exceptional students from around the world are: Saul Durand (Jovan Adepo), Auggie Salazar (Eiza González), Jin Cheng (Jess Hong), Jack Rooney (John Bradley), and Will Downing (Alex Sharp). Under her tutelage, they become a very close group of friends. In 2016, all in the group graduate, except for Jack, who has dropped out to form his own snacks company.

What happens in the present day in 3 Body Problem?

In the present day, the San-Ti’s Sophons arrive on Earth, causing all the major particle accelerators around the world to start generating results that make no sense, including the one in Vera Ye’s lab where Saul works as her research assistant. Shortly after that, Vera reads her mother Ye Wenjie’s (now played by Rosalind Chao) communications with Mike Evans (now played by Jonathan Pryce), whom she never knew was her father, and learns that they invited the San-Ti to invade Earth.

One night, Vera kills herself and doesn’t leave a note. The Oxford Five reunite for Vera’s funeral. After the funeral, Ye Wenjie gives Jin a headset to play a virtual reality game, where the task is to “solve the riddle of this world.” Jack later joins her in the gameplay. In reality, the San-Ti created the headsets to recruit the world’s top minds to help ease their arrival on Earth. 

Auggie starts seeing a countdown in front of her eyes. Tatiana (Marlo Kelly), a devout believer in the San-Ti, advises her to halt her work on nanofibers to make the countdown stop and suggests she watch the sky the following night at midnight. Meanwhile, Da Shi (Benedict Wong) and his boss, Thomas Wade (Liam Cunningham), are investigating the mysterious deaths of scientists around the world, many of whom were also seeing numbers like Auggie. 

The next night, the entire world sees the stars wink at them, in a sequence that matches Auggie’s countdown numbers in something akin to Morse code. She stops working on her project and her countdown ceases. For now.

A few days later, Will tells Jack that he has a fatal pancreatic cancer diagnosis. Jin discovers that the planet in the VR game has a three-body problem. Outside the game, Tatiana invites Jin and Jack to a meeting in London where they learn the truth: The San-Ti created the headsets to recruit the world’s best minds because it’s actually their planet that has the three-body problem. Since their home is uninhabitable, they’re leaving it and heading to Earth. Jack is skeptical about the whole notion of aliens coming, so Tatiana murders him. 

On Nov. 8, Mike Evans reads “Little Red Riding Hood” to the San-Ti as part of his daily contact with them. But once they learn from him that humans can lie, they cut off all contact out of fear. At the conference later that night, Jin learns that Ye Wenjie and Mike Evans are the founders of the movement for the San-Ti. Wade’s forces crash the summit and Tatiana starts a shoot-out. Ye Wenjie gets arrested, and Auggie resumes her nanofiber work without seeing a countdown, which means the San-Ti aren’t protecting their flock anymore…

Ed Miller

When are the San-Ti coming in 3 Body Problem?

Four hundred years from now, the San-Ti will arrive on Earth. But will humanity be ready? 

Discover the truth about the 3 Body Problem with the Oxford Five, now on Netflix.