Credit: Vivian Zink/ABC Television Group © 2012 Disney Photo: Callie With a Little Girl on Grey's Anatomy Season 8, Episode 13

The Grey's Anatomy alternate reality episode (Season 8, Episode 13: "If/Then") is tonight. Finally. For those of you who can't wait until the episode airs to get a hint of what it's like through the looking glass, we've gathered all the sneak peeks together right here, so you can watch them on endless loop, dissecting every changed wardrobe and odd relationship.

Spoiler-phobes, this post is for you: We won't reveal anything not shown in official promos.

First, you can watch the first 10 minutes of the episode right here! From Meredith's (Ellen Pompeo) engagement to a cheerful Alex (Justin Chambers) to Callie (Sara Ramirez) and Owen's (Kevin McKidd) adorable kids, there's more than enough WTF?! here to keep you going until tonight.

Credit: YouTube Photo: Grey's Anatomy Sneak Peek: The First 10 Minutes of Season 8, Episode 13: "If/Then"

However, if that's not enough, we also have this clip, which suggests there's trouble in Derek (Patrick Dempsey) and Addison's (Kate Walsh) seemingly picture-perfect marriage.

Credit: ABC © 2012 Disney ABC Television Group Photo: Preview Clip of Grey's Anatomy Season 8, Episode 13: Addison and Dereks Tension

Finally, this sneak peek repeats a lot of the most interesting scenes from the first ten minutes, and also has a few new ones at the end. Skip to 1:50 to see more couple-y weirdness between Callie and Owen, and to hear punked out Lexie (Chyler Leigh) speak.

Credit: the Hollywood Reporter Photo: Grey's Anatomy Sneak Peek of Season 8, Episode 13: "If/Then"

Remember to tune in to the episode on Thursday, February 2, at 9 pm ET/PT on ABC.

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