Ballroom dancer Val Chmerkovskiy and actress Rumer Willis have special plans in store for Monday night's "Dancing With the Stars" finale on ABC. ABC

It’s almost time for the last song of the night for Season 20 of “Dancing With the Stars.” Actress Rumer Willis and dancer Val Chmerkovskiy have been working on something special for their fans.

Sources tell Us Weekly that Willis, 26, and Chmerkovskiy, 29, are planning an action-packed freestyle routine to Britney Spears’ 2003 hit “Toxic.” The duo won’t only dance to the tune, they’ve helped record it too. Willis, who previously covered Miley Cyrus’ “Wrecking Ball” and Adele’s “Rumor Has It,” supplied the vocals for the cover while her partner Chmerkovskiy will re-create the song’s violin track.

The source said the pair created a “sexy, cool arrangement” of the song. “Rumer's thrilled to finally share it with the world!" Well, Chmerkovskiy couldn’t wait for Monday night’s episode of “Dancing With the Stars” to share a little tease of the song in progress. He posted a picture of his time in the studio with Rumer Willis on Instagram saying, “... excited for you all to hear it!”

Earlier in Season 20, the couple had to brush off dating rumors after another couple, ballroom dancer Kym Johnson and “Shark Tank” host Robert Herjavec, made theirs official. Last week’s sensual round with a “Fifty Shades of Grey”-inspired dance did little to quell the rumors.

Willis and Chmerkovskiy will compete for the Mirrorball Trophy against remaining couples Riker Lynch and Allison Holker, and Noah Galloway and Sharna Burgess.

The “Dancing With the Stars” finale will air Monday at 8 p.m. EDT on ABC.