Three friends see their lives and futures change forever after the Earth is mysteriously enveloped by a membrane that cuts it off from the rest of the universe. Twelve year old Tyler Dupree and his friends, twins Jason and Diane, are out stargazing near their home when they witness all the stars suddenly going out.
It turns out to be a global phenomenon, Earth has been surrounded by an dark membrane that obscured the rest of the universe and destroyed our satellites. Dubbed the “spin membrane” it includes a false sun within it to sustain life, so it is clearly artificial. Later it is discovered that two large objects over the poles control it.
As they grow up, Tyler and Jason remain friends despite their class differences. Jason and Diane's father E.D. runs an aerospace company called Perihelion, and was best friends with Tylers own father who died when Tyler was a boy. His friendship with Diane drifts in and out as she becomes more religious and obsessed with the growing Christian apocalyptic movements. He and Jason remain also remain in touch, and E.D pays for Tyler's medical school.
Jason joins his father's aerospace company as Earth struggles to replace the satellites that fell to earth during the first night. New satellites are launched and it is discovered that 3.7 years are passing outside the field for every single second on the surface of the planet, which means that in just a handful of subjective decades the Sun will go supernova and destroy the planet.
Diane's religious views become even more extreme and she joins a cult and drifts from Tyler's life. Tyler continues his education and becomes a doctor. Life mostly goes on as normal, with the exact doomsday date uncertain.
The three friends get together for a rare weekend getaway, during which there is an attack by the China on the polar objects. The attack is unsuccessful but causes ripples in the membrane, Diane confesses that she has feelings for Jason and he admits he always loved her, but although they make love that night she returns to her fiance the next day.
Jason reveals to Tyler that Perihelion is building a spacecraft to send to Mars in hopes of terraforming it and establishing a colony. The quickened pace outside the spin membrane will mean millions of years of terraforming will take just a few subjective months, giving hope for species survival and maybe an answer to mystery of the membrane, since the Martians will be able to advance further than Earthlings.
He also hires Tyler to work as a doctor for Perihelion, and reveals that he has been feeling unwell but been afraid to go to a doctor in case he gets sidelined by the company. Tyler diagnoses him with multiple sclerosis and treats him in secret. They grow closer during this period and have long talks about the membrane, the intelligences behind it, and their lives.
The Mars mission is a success, and within two Earth months Mars is inhabitable and colonists are sent. Two years after that there are clear signs of civilization on the red planet. And then it is suddenly surrounded by an identical membrane.
However the Martian civilization has managed to send a spacecraft to Earth containing a single ambassador. Their civilization is now much older than ours, and their technology very advanced. Their biotech is able to cure Jason's multiple sclerosis with a life extending treatment. They use this to extend the lives of those who chose to undergo treatment by five or six decades, becoming what they call Fourths, referring to a Fourth age past Adulthood. Fourths experience psychological changes as well, and are considered wiser and more mature.
Perihelion uses Martian technology to develop and send nanotech machines through the Solar System and beyond, looking for other planets enveloped in membranes. The Earth governments become paranoid about the Martian life extension biotech and declare it, and by extension any Fourths who have taken it, to be illegal.
Meanwhile Diane falls ill from a disease spread by the cattle her doomsday cult was raising, and her husband calls Tyler for help. He arrives to find her nearly dead and rushes her back to Jason, hoping to use the Martian biotech to cure her. But Jason has relapsed and is very ill himself, causing Tyler to worry about the cure. However Jason assures him the Martian biotech is sound and he reveals that he underwent further Martian treatments in order to communicate with the nanotech machines they sent up, leading to his current condition.
He also reveals what he has discovered from the nanotech machines about the membrane; it was created by intelligent machines that were essentially trying to put biological civilizations on the verge of collapse into a form of stasis until a “cure” could be found to stabilize them.
Diane takes the Martian medicine and is cured, becoming a Fourth as well but essentially an outlaw due to her use of the Martian biotech.
The membrane collapses briefly, revealing a dangerously aged sun, then it comes back dimmed, now serving only as a filter from the aging Sun's radiation. It turns out that a new mysterious object has descended during this time, dubbed The Archway. It is actually a huge ring that has descended from space and partially submerged itself in the ocean. It turns out to be a portal to a distant world which has been engineered to support human life. It appears to be the “cure” that the mysterious creators of the membrane have created for humans.
At the end of the book Tyler takes the same Martian medicine that Jason and Diane did, extending his own lifespan and becoming a Fourth. He and Diane, who are on the run from the authorities now, go through the Archway together.
Best part of story, including ending:
The central mystery is very cool and the basic concept both very simple (a shield that slows Earth down) but with huge ramifications.
Best scene in story:
The description of the night of the blackout is well done, and realistically underplayed, its such a huge thing to happen but so undramatic that you can believe people would not really know how to react to it.
Opinion about the main character:
Tyler is an everyman, meant to be the point of view character at the center of monumental events, so he's sympathetic but not as interesting as hyperintelligent Jason or crazy/passionate Diane.