stumbled on to something and he is trying to figure out a way to use it. Ultimately he would like to use it for good, but in so doing he causes a lot of damage. So I guess you can say he's obsessed. And this particular point in time where the episode of Fringe starts, time is fleeting and he's just... under the gun." On his character's possible reappearance, Ruck commented, "I think not... Technically yes [he could come back], but probably not." As with other Fringe episodes, Fox released a science lesson plan in collaboration with Science Olympiad for grade school children, focusing on the science seen in "Os", with the intention of having "students learn about meteorites and ways of finding them." Reception Ratings On its first broadcast, "Os" maintained a 1.5/5 rating share for adults between the ages of 18 and 49 as with several previous episodes, with an estimated 3.76 million viewers. In the 18–49 demographic, Fringe was the second most watched show in its time slot, after CSI: NY. Time shifted viewing increased the episode's ratings among adults by 53 percent to a 2.3 ratings share. This was the largest increase in time shifting viewing for the week among network shows. Reviews Reviews of the episode were generally positive. Ken Tucker from Entertainment Weekly praised guest actor Alan Ruck's "sustained, understated" performance, and also called Olivia being revealed as Bell's vessel "a clever development," especially praising actress Anna Torv's imitation of Nimoy's voice rather than "doing the obvious thing and hav[ing] her lip-synch Nimoy reading the lines." The A.V. Club's Emily VanDerWerff graded the episode with a B−, explaining that unlike Tucker, she thought the idea of "soul magnets" was "just so goofy that it's almost too much for me to handle". VanDerWerff also felt there wasn't much of a connection between the episode and the ongoing storyline "until the show tries to force one in a way that doesn't feel as elegant as the show usually makes this stuff feel". She did however praise Ruck as "well-cast," and wrote the episode "very nearly managed" to parallel Walter's "desperate measures to the desperate measures of other men also trying to save themselves or their children through science," which the reviewer considered the strongest asset of the show. Writing for the Los Angeles Times, critic Andrew Hanson referred to audiences' Friday night plans away from television