Spoiler policy: If you want to discuss a plot point from an upcoming episode, something you know is going to happen because it’s been revealed in interviews or some other canon source, including the preview for the following week, put it in a spoiler box, and label the box so we can decide for ourselves whether or not it’s something we want to know (example here). If you’re simply speculating about what might happen in an upcoming episode, or if you’re discussing something that has already aired in the episode (not including the preview), there’s no need for a spoiler box.
This week’s episode title: “Someone to Watch Over Me.” Written by David Weddle & Bradley Thompson; directed by Michael Nankin. On this basis alone, the episode should be a good one: Weddle & Thompson are among the show’s strongest scripters (“Act of Contrition,” “The Hand of God,” “Scar,” “Downloaded,” “Exodus 1 & 2,” “Revelations,” and many more), and several cast members have said that Nankin is their favorite director.
Regarding episode numbering, see comment here. Note also that on the scifi/battlestar site, this is officially episode 419, despite what’s found on other sites.
Sci-Fi’s preview for the episode. Also, from Canada’s Space network, a not-so-different preview. Spoilers in both.
Links to previous threads:
4.13 - “Sometimes a Great Notion” (in which the discovery of the ruined Earth has serious repercussions for the fleet, and various people melt down and give up: Roslin burns her scriptures, Adama begs Tigh to kill him, and Dee shoots herself, among others; the Penultimate Four experience flashbacks while on Earth, and realize that they lived there two millennia ago; Starbuck finds her own corpse in the wreckage of her viper, and Leoben wigs out; and Ellen Tigh is revealed as the Final Cylon)
4.14 - “A Disquiet Follows My Soul” (in which Adama presses the fleet to tolerate the Cylons and adopt their technology, causing resentment to grow in the fleet, including among Colonial officers, chiefly Gaeta, who begins plotting resistance efforts with Zarek, while Baltar stokes negativity of his own; Tyrol discovers he’s not the father of his child; and Roslin finally joins Adama in his bunk)
4.15 - “The Oath” (in which mutiny explodes, led by Zarek and Gaeta; all known Cylons on Galactica, except Tyrol, are confined in the brig; and Tyrol helps Roslin and Baltar flee the battlestar, with the assistance of Adama and Tigh, who have escaped their own captors, and who choose to stay behind to defend their ship)
4.16 - “Blood on the Scales” (in which the mutineers target Adama for execution; Roslin and Baltar escape to the basestar; Zarek has the Quorum liquidated; Adama, aided by Starbuck, Apollo, and Tyrol, retakes his ship, though Anders is badly injured; and Zarek and Gaeta eat a firing squad’s bullets for their crimes)
4.17 - “No Exit” (in which Cavil secretly resurrects final-Cylon Ellen Tigh, and Anders unexpectedly begins recovering final-five memories due to his brain injury, both of which storylines result in a metric frakload of backstory being shoveled into the audience’s lap; in other developments: Roslin recruits Lee to help her hold together the remaining tatters of government; Boomer spirits Ellen off Cavil’s basestar; and Tyrol convinces Adm. Adama to allow a Cylon-tech fix to Galactica’s overstressed frame)
4.18 - “Deadlock” (in which final cylon Ellen Tigh returns to the fleet, and has a jealous freakout over Saul-and-Caprica’s pending pop tart, which drives her to cast the tiebreaking cylon vote in favor of a cylon withdrawal; Adama is losing control of his own ship due to an implied shortage of Marines; Baltar pushes his cult to stand up to local thugs, who are operating with impunity because of the aforementioned shortage, and who laugh at the cult’s effort to resist; Adama stares at his ship’s skeleton a lot, before deciding to arm Baltar’s cult; Caprica Six suffers a miscarriage; and Anders might be waking up)
And thus do we barrel toward our finale.