Carlos PenaVega, Witney Carson, <em>Dancing with the Stars</em> Carlos PenaVega, Witney Carson, Dancing with the Stars

And then there were four.

Since Tamar Braxton was forced to leave the competition last week, we have a quartet of contestants competing in the semifinals of Dancing with the Stars. Who will make it to next week's finals? Read on to find out.

For the first time in the show's history, the semifinals will require each contestant to perform three dances - one individual routine, one new dance as part of a dance-off, and a trio round.

And, for all the Dancing truthers who questioned whether Tamar's last-minute arrival was staged last week, Val Chmerkovskiy and Tom Bergeron give us a play-by-play about what exactly happened with Tamar last week,. (It wasn't.)

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First round: Individual dances

Bindi Irwin and Derek Hough (salsa)
The dance: Bindi's had some heavy material to work with in recent weeks, especially with the tributes to her late father, so it's a treat to see her really cut loose and look like she's unabashedly having a good time with this salsa. (Falling backward into the crowd at the end is a nice touch too.) Her smile detracts a little from the footwork, but like Bindi herself it's uplifting and a joy to watch.
What the judges say: Julianne wanted more "down and dirty" from their salsa, but admits that the music lent itself to a lighter routine. Bruno and Carrie Ann love the dance overall, but also tell Bindi that her hips could have used a little more edge.
Score: 27 (out of 30)

Alek Skarlatos and Lindsay Arnold (waltz)
The dance: Of course Alek's waltz is set to "America the Beautiful." Does that mean that anyone who doesn't like it is unpatriotic? Hopefully not, because the routine is just okay. Alek just doesn't have the effortless grace required to pull off what I assume was intended to be a soaring sendup of all kinds of emotions. Instead, it ends up being just a somewhat awkward attempt at poignancy. 'Merica! Tom does ask Alek about the Paris terrorist attacks, which he says "really hit home." (The train Alek was riding when he and two friends thwarted a gunman, remember, was bound for Paris.)
What the judges say: Bruno can't believe how far Alek has come in the competition and says his turns were spot-on. Carrie Ann thinks this is Alek's best performance so far. Julianne tells Alek he showed an unprecedented level of comfort.
Score: 30

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Carlos PenaVega and Witney Carson (contemporary)
The dance: There is literally not an ounce of fat on Carlos' body. I'm sorry, I know this is a dancing competition, but can we just talk for a second about his incredible physique? I'm in awe. Anyway, this becomes Gymnastics with the Stars for a couple of minutes, with Carlos dancing with a rope almost more than he dances with Witney. He's super into it in a way that could be seen as overdramatic, but the routine is so physically impressive that this doesn't become an issue. Next stop, Cirque du Soleil?
What the judges say: Carrie Ann has mixed feelings because she "didn't get it" and Carlos overdid it in his face. Julianne says Witney and Carlos seem to be losing their connection a bit. Bruno dismisses them both and calls the routine "bloody good."
Score: 28

Sharna Burgess and Nick Carter (tango)
The dance: Nick's arms looked better in rehearsal than they do here. And I can't help but wonder if he's distracted by the package about his sister's overdose, because he looks totally out of it for the majority of the routine and his feet are all over the place. The last 10 seconds or so of the dance are great, but otherwise it's a mess.
What the judges say: Julianne is "so sad" that the dance was so bad, but compliments Sharna for her mini-pep talk in the middle. Bruno says their chemistry "sizzles" and advises Nick to forget about the mistakes. Carrie Ann tells Nick she knows he's going to rebound in the next two dances.
Score: 24

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Round 2: Dance-off

Carlos/Witney vs. Alek/Lindsay (cha cha)
The dance: This is better than Alek's waltz, but poor Alek can't hold a candle to Carlos' natural charisma (and, if we're being frank, abs). it's like the JV team versus varsity here, and there's really no contest.
What the judges say: Julianne compliments Alek for still being waxed, but says he lost the musicality at points, while Carlos' technique was "spot-on." Bruno judges the "chest-off" and critiques Alek's "wiggly bum" and arm movements, which he likens to an eagle. Carrie Ann says the guys were polar opposites in their technique, but both delivered.
Winner: Carlos/Witney

Bindi/Derek vs. Nick/Sharna (samba)
The dance: Bindi apparently took the salsa criticism to heart, and gives us some extra "bum wiggles," to borrow Bruno's terminology. Nick's samba, likewise, is an improvement over his tango. They're certainly more evenly matched than Alek and Carlos, and the judges have a tough choice ahead of them.
What the judges say: Bruno marvels at the amount of content in both the dances, but gives the edge to Bindi and her newfound passion. Carrie Ann is glad that Nick finally got out of his head, but is also Team Bindi. Julianne makes it unanimous, but also tells Nick that he "brought it."
Winner: Bindi/Derek

Round 3: Trio

Bindi/Derek/Mark Ballas (jazz)
The dance: Bindi's had some issues with timing and synchronicity before, but not so much here. Derek and Mark's choreography is predictably awesome, and Bindi going to town on that rope lightbulb brings out a darkly intense side of her that we haven't seen before. (What is with tonight and ropes, anyway?)
What the judges say: Julianne tells Bindi she's a "little ninja warrior princess" who didn't miss a beat. Bruno says the dance was "a work of genius," and Carrie Ann makes a bunch of sound effects and calls the dance something that a professional dance troupe could have done.
Score: 30

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Alek/Lindsay/Emma Slater (Argentine tango)
The dance: Despite what Alek says about not being able to handle two women at once (especially when one of them is Emma), this dance plays to Alek's strengths - literally. He makes the girls look light as a feather with the lifts, and he's clearly most comfortable when he's the statuesque, intense pillar anchoring the dance in place.
What the judges say: Bruno tells Alek he "handled the threesome like an expert." Carrie Ann says the dance lost a bit of steam at the end, but was otherwise excellent. Julianne agrees that it petered out a bit in the final moments, but loved the choreography.
Score: 27

Carlos/Witney/Karina Smirnoff (Charleston)
The dance: You'd never know we had three Charleston rookies on the stage for this dance. Granted, they're not in perfect sync 100 percent of the time, but pretty close to it. And there's so much content in this that it's impressive Carlos doesn't miss a step. I feel like the judges were a bit harsh on Carlos for his first dance, but there's hardly anything they could find fault with here.
What the judges say: Carrie Ann says the dance was fun and she couldn't take her eyes off of it. Julianne and Bruno tell Carlos that he stole the dance from the ladies, with Bruno comparing him to Charlie Chaplin.
Score: 29

Nick/Sharna/Peta Murgatroyd (salsa)
The dance: Peta's back! And looks like she's completely recovered from her injury. This is hands-down better than Nick's first dance, but unfortunately it's probably the weakest of the trio dances. (Sorry, but the previous three set the bar pretty high!) The choreography is more flash than substance, and Nick maintains a great energy level for most of the routine, but definitely starts to look sluggish towards the very end.
What the judges say: Julianne praises Nick for stepping up during "do or die" time. Bruno also loved it, saying the dance embodied all of Nick's strengths. Carrie Ann tells Nick this is the most solid he's ever been.
Score: 30

And now for the most important part of the night - who's heading to the finals? Surprise, surprise ...

Safe: Alek and Lindsay, Carlos and Witney

In jeopardy: Bindi and Derek, Nick and Sharna

Twist! Because of Tamar's withdrawal, no one is eliminated tonight, and we'll have a four-person final beginning next Monday.

What did you think, Dancing fans? What was your favorite routine of the night? And who are you rooting for in the finale? Sound off in the comments!

Part 1 of Dancing with the Stars' Season 21 finale airs Monday at 8/7c on ABC.