Twelve celebrities take to the dance floor to perform; Jason Derulo performs. Celebrities: Sean Avery; Candace Cameron Bure; Drew Carey; Billy Dee Williams; Charlie White; Cody Simpson; Amy Purdy; Diana Nyad; Danica McKellar; James Maslow; NeNe Leakes; Meryl Davis

Before the series started, celebrities were asked which dance they were most excited to learn. Now, they perform the dance that they unwittingly picked. And the couples are faced with another surprise - a double elimination.

Robin Roberts joins the judges panel for this week's competition as couples perform dances inspired by the stars most memorable years.

Julianne Hough returns to the show as a guest judge as the contestants face their toughest challenge yet. In a series-first, they switch partners for the competition based on the home audience's Twitter votes. The episode also saw the return of the Macy's Stars of Dance, choreographed by Derek Hough.

The couples are back with their original partners and Donny Osmond joins the judges panel for Disney night. With the help of some Disney magic, some of our favourite Disney characters find their way into the dances.

Redfoo joins the judges panel this week for a rocking Party Anthem Night as another couple faces elimination. Derek Hough choreographs another electrifying Macy's Stars of Dance number, featuring Kryoman, to Martin Garrix's hit song 'Animals'.

The show kicks into high gear with Latin Night, with - who else? - Ricky Martin joining the show as a guest judge and performer. The couples perform two dances tonight - an individual dance and the much-loved team dance. However, injuries begin to take their toll, especially among the ladies, leading up to the team dance.

DWTS's very own Mark Ballas opens the show with his new single 'Get My Name'. After performing their individual dances, the couples pair up to perform another series first - synchronized dance duels. Despite the name, the couples work together to achieve the highest score for their combined performance. Combined with their individual scores, the celebrity with the lowest tally faces elimination.

The semifinalists performed two unlearned dances to songs by American music icons. As the pressure starts to build, the rhe celebrities were also able to speak draw inspiration from the people who they consider "icons". Candace, Charlie, Amy, James and Meryl each received advice from Angela Thomas, Scott Hamilton, Oprah Winfrey, L.A. Reid and Kristi Yamaguchi respectively.

The final four couples compete in two rounds of dance, one in which they repeat the same style of dance they did on the week of the Switch-Up, and one in which the perform an elaborate freestyle dance with special effects, guests and surprises.

After weeks of grueling practice and intense performances, the finalists will finally learn which celebrity and professional dance partner have won the coveted Mirror Ball trophy when Tom Bergeron makes the much-anticipated announcement.