123Movies. Principal Dancer is a mesmerizing look on how a young artist's journey is defined by his ability to challenge his own limits and to reinvent himself. Brazilian hip-hop performer turned into Royal Ballet's principal dancer Thiago Soares unveils the backstage of the Royal Opera House, in London, as he rehearses alongside some of the most outstanding names in contemporary dance - and prepares to go back home, in Rio de Janeiro, where he'll face one of his life's most challenging presentations.