He was baaack. Dancing With the Stars was livelier than ever Monday night with the return of bad boy pro Maks Chmerkovskiy. He and pro dancer faves Chelsie Hightower, Tony Dovolani, Anna Trebunskaya and Tristan MacManus returned for a special dance challenge. But before the performances got underway, host Tom Bergeron addressed the audience about the Boston Marathon bombing. "Our thoughts are with everyone in Boston tonight. I have family members and many friends there. My heart is with you," said Tom. Co-host Brooke Burke-Charvet added that the "entire cast has been thinking about you. And, as always, our show is planned in advance and hopefully we can still have an entertaining night of competition for you." Tom continued to repeat the message throughout the show. It was "Len's Side-by-Side Challenge" week. Stars and their pro partners had to dance a portion of their dance side-by-side next to pro couples, requiring that the couples be in sync and making any errors obvious. Judge Len Goodman said it would be the "toughest" challenge yet. Here's how he and fellow judges Carrie Ann Inaba and Bruno Tonioli rated the nine competing stars:
