When a capsule containing Martian specimens is brought aboard the International Space Station, scientists discover the first proof of life outside Earth.

At first this Martian life form looks almost cute. But what follows is the biggest custody battle in history, a battle for survival that makes the movie "Life" an edge of your seat thriller.

“It’s like being on a roller coaster without all the vomiting,” says Ryan Reynolds.

“Or with the vomiting,” adds Jake Gyllenhaal.

The movie "Life" teams up the A -listers and best buds Jake Gyllenhaal and Ryan Reynolds, who bonded by cracking each other up during the making of this very challenging, very intense film.

Neither actor had any idea what the life form looked like when he was making the film.

“I just pictured Ryan,” said Gyllenhaal.

“Me without pancake make-up,” deadpanned Reynolds.

Though shot in the same London studio as Beauty and The Beast, Life takes place in zero gravity. Scenes featuring the astronauts swimming through space involved numerous wires and a stunt team acting almost like puppeteers.

“Each separate actor had people pulling them right or left or keeping them in the air,” said Gyllenhaal.

“Yeah, they're the real heroes too,” said Reynolds. “For us, it was challenging to move around like that. But these guys? What they did was art.”

"Life" works as a thriller as long as you don't stop to question the dumb decisions made by people smart enough to be the world's top astronauts.