Fringe: Os

"Os" is the 16th episode of the third season of the American science fiction drama television series Fringe, and the 59th episode overall. The episode centered on the Fringe team's investigation into a series of robberies of the element osmium, which they connect to a scientist (Alan Ruck) who is able to defy the laws of physics. "Os" was written by Josh Singer and Graham Roland, while Brad Anderson served as director. Along with Ruck, the episode also guest starred Jorge Garcia in a brief cameo as a security guard. On its first broadcast in the United States on March 11, 2011, an estimated 3.76 million viewers tuned in, giving it a 1.5/5 ratings share for those between the ages 18–49. Critical reception to the episode was generally positive, as multiple critics noted that Ruck was well-cast as a scientist just trying to help his son.