This week's Gossip Girl episode was grim, slower-paced and more somber than any so far this season, but after the events of the Sinners & Saints party, you can see why.

The show is no stranger to depressing holiday installments, with "Gaslit" now ranking among the darkest. A drugged and missing S will kill any festive Thanksgiving mood.

To sum up: Nate's father is shady, Chuck and Blair make great friends, Serena is troubled, and Katie Cassidy will go down as one of the best villains in Gossip Girl history.

She will go down in a different sense, too. Dair will see to that.

A TROUBLED YOUNG WOMAN: Juliet's plan was brilliant in its believability.

Waking up in a daze, poor Serena has no idea where she is (a Queens motel) or how she got there, calling 911. At the hospital, Lily commits her eldest child to rehab involuntarily.

We're not sure that's even feasible unless the person is deemed mentally incapable of making their own decisions (see Spears, Britney, circa 2008), but that's what Lily decides.

Perhaps that's why the writers threw in that an antidepressant was found there, so that Serena, an adult, would be deemed a suicide risk and lose control of her own decisions?

In any case, Lily and Blair worry about her "past" and act like this is not all that unusual. To Dan, and viewers, it certainly would be. That's why he's the sole member of Team S.

Dan believes her when she swears she didn't do drugs. Then he breaks her out of rehab and, naturally, before feeling NYC, they regroup at the loft. Lily and Blair find them there.

Worst. Fugitives. Ever.

Whatever his motivations for helping Serena, Dan calls Lily out on her parenting, and she has a moment of clarity ... until Gossip Girl shakes things up with a pic of S doing coke.

Of course, the photo is actually Juliet, the final stage of her plan. Serena can't believe that she did that at the party and can't remember, so she checks herself back into rehab.

Around this time, Jenny and Vanessa are feeling guilty about how far they've taken things, but Juliet convinces them that whatever Serena did after the party is not their fault.

Vanessa cracks and sells out Jenny as the sole culprit. Wow, V. When Jenny goes to confront Juliet, she finds her apartment empty, save for a mask. The pieces come together.

Before accepting her banishment and heading home to Hudson once again, J reports her discovery to Blair. With no Jenny to play double agent, B recruits the other Humphrey.

It's a little unclear why Jenny didn't tell Rufus and Lily, or why Blair sought Dan's help first (he will do anything for Serena), but that's where we stand heading into next week.

Watch out, Juliet. Frontier justice is coming and it's going to end badly for you.

THE EVIDENCE: Ashamed, Jenny presents it to her nemesis.

Elsewhere, there were some interesting developments inside jail. Apparently Juliet didn't let Ben in on her plan to drug Serena, and even he thinks that was over the line.

This makes for an interesting twist. Even though this whole thing was his doing, might Ben turn against his own sister in the end? Will Serena and he come face to face?

Ben's cellblock mate, The Captain, also figured prominently in "Gaslit," as Nate begged his mom to give her incarcerated spouse a chance before filing for divorce. She did.

At the end, we learn that Nate's father may have only reached out to the family because he's coming up for parole, and family support may garner the board's sympathy.

Think that was his real motivation? How will Nate respond to this revelation?

Some closing Gossip Girl thoughts before we turn it over for your comments:

• Juliet is BALLSY for continuing to extort money from Lily after what she pulled. Falling off the radar would be much smarter, but this girl has no inhibitions.
• When Vanessa walks into Lily and Rufus' for Thanksgiving only to find everyone gone? Unintentional LOL material. V's character summed up in one scene.
• Chuck and Blair's love story was on the back burner, but still handled beautifully. Just because they can't be friends doesn't mean they aren't. Swoon.
• Was this the first real screen time of the fall for L and R?
• It's getting annoying how Jenny keeps leaving for no reason.
• Aww, french fries on Thanksgiving ... we've come full circle.
• Dan and Serena's kiss: The first of many? OMG or WTH?
• Dorota and her baby are sooo cute, right?

What did you think of this week's Gossip Girl? Share your thoughts on "Gaslit" and predictions for next week by leaving comments below!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.