Director Steven Soderbergh's big trick is the deadly rate at which the virus grows. Almost every scene for the first hour, someone gives a number, and it's always bigger. Soderbergh and his editor Stephen Mirrione cut from surface to surface, place to place, showing the spread of the unnamed, unknown contaminant at such a stomach-turning pace, it's hard not to wonder if beating a virus like the one in the movie would be impossible. Things start to spin out of control when Beth (Gwyneth Paltrow) returns home from a work trip overseas with a bit of a cough, and within days, she's collapsed on the kitchen floor while her husband Mitch (Matt Damon) tries to shoo his son out of the room.

Once the contagion is considered a national threat and of global interest, Soderbergh switches gears, flipping between the various members of his vast ensemble cast as they take action. Jude Law is memorably slimy as a notorious blogger named Alan Krumwiede, who pokes around looking for proof that the government's interests don't match up with the public's. Soderbergh wisely prevents political undertones from taking over the thread, while allowing Law to craft a character who walks the line between endearing and disgusting. At the Center for Disease Control, Dr. Ellis Cheever (Laurence Fishburne) and Dr. Ellen Mears (Kate Winslet) start trying to contain the spread of the illness and find ways to help those who have already gotten sick. Cheever is a veteran and Mears is a newcomer, and Winslet nicely tinges her character's authoritative moments with a hint of uncertainty and inexperience underneath. Similarly, Cheever has a fatigue about him brought on not so much by stress but by frustration, both at those who surround him and his inability to make things happen as fast as they need to. Most of their scenes are over the phone, but there's a familiarity between them that bridges the gap.

On the other hand, a subplot about Dr. Leonora Orantes (Marion Cotillard) heading to China to work with Sun Feng (Chin Han) in trying to trace the disease's point of origin is less effective. The first half of the story, with Cotillard's character scanning videotapes and looking for clues, is fascinating, but the turn it takes from there is weird, and Scott Z. Burns' script doesn't offer Cotillard enough character development (her motivation in later scenes is very unclear). Parts of the film's ending are also not as satisfying as what came before (particularly the conclusion of Cheever's story and his interactions with a minor character played by John Hawkes). Thankfully, neither of these elements eat up a significant amount of time, and Soderbergh goes out on a strong, compelling note.

It's cliche, but true: Contagion gets under your skin. Although the film is about a disease that might not ever arrive, it also paints a picture of a world faced by a crisis that it has no easy method to fight, and people who have no idea how to react. With each growing number of affected areas and people, even the good guys, the people who are fighting as hard as they can to keep things under control and save lives, can't help but feel like they're facing a problem far beyond their means. Without an understanding of the enemy and without an obvious solution, fear begins to spread, and Soderbergh spreads that fear off the screen and into the viewer.