Dr. Ryan Stone, a brilliant medical engineer on her first shuttle mission, accompanies veteran astronaut Matt Kowalski, who is commanding his final mission. During a seemingly routine spacewalk, a disaster strikes. The shuttle is destroyed, leaving Stone and Kowalski completely alone - tethered to nothing but each other and spiraling into the blackness. The deafening silence tells them they have lost any link to Earth and any chance for rescue. As fear turns to panic, every gulp of air eats away at what little oxygen is left.

The catastrophic destruction of their shuttle was due to a cloud of debris from a destroyed satellite, which is now hurtling around Earth at breakneck speed, shredding everything in its path. This presents the survivors with a dire situation: they must make their way to another space station to seek refuge and safety. With no hope of rescue, Stone's resolve is put to the ultimate test, forcing her to confront the prospect of a solitary existence in the vast emptiness of space. Trapped in an environment where the only enemy is time itself, Stone and Kowalski must work together to find a way back home against seemingly insurmountable odds.