Spoiler policy (revised as of last week; please make note): 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.
Regarding episode numbering, see comment here. Note also that in the link to the preview below, and on the official scifi/battlestar site, this is officially episode 417, despite what’s found on other sites.
This week’s episode title: “No Exit.” Written by Ryan Mottesheard; directed by Gwyneth Horder-Payton. (This is Mottesheard’s first writing credit, though he’s been a script coordinator on the show since season two; Horder-Payton has not worked on BSG before now, but directed several episodes of “The Shield.”)
Sci-Fi’s preview for the episode. Also, from Canada’s Space network, a very different preview. Middling spoiler in the first, potentially significant spoiler in the second. Click at your own risk.
Links to previous threads, for anyone who wants to review:
4.8 - “Faith” (in which Starbuck’s crew finds the wounded basestar, and Roslin deteriorates in Galactica’s sickbay)
4.9 - “Guess What’s Coming to Dinner” (in which Starbuck’s crew returns with the basestar; Gaeta sings about his missing leg; the Cylons propose destroying the Resurrection Hub, and then immediately begin scheming to betray humanity while the humans do the same; Athena murders the Six Natalie; and Roslin gets “kidnapped” when the hybrid panics and jumps)
4.10 - “Sine Qua Non” (in which the disappearance of Roslin prompts a search for a replacement President, and erratic behavior from Adama; Cottle reveals that Tigh has impregnated Caprica Six during his “interrogations”; Lee is chosen and sworn in as interim President; Adama relinquishes command to search for Roslin; and the character of Romo Lampkin is made considerably less interesting)
4.11 - “The Hub” (in which Roslin’s isolated basestar crew, human and Cylon together, cooperate to destroy the Hub without the help of the fleet)
4.12 - “Revelations” (in which a mutually-assured-destruction standoff is resolved when Lee abruptly finds a compromise to achieve a tentative peace, and human and Cylon gaily traipse off to the now-known location of Earth, only to find it was turned into a radioactive cinder long ago)
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)
And thus does the countdown continue…