Spears felt inspired to create a show with a hotel theme which she later mixed with the concept of an onyx stone.
Mystic Lounge featured an homage to Cabaret and other musicals, while remixing some of Spears's early hits.
Security Cameras was the raciest part of the show, with Spears and her dancers emulating different sexual practices.
On December 2, 2003, Spears announced through her official website US concerts to support her fourth studio album, In the Zone (2003).
On February 17, 2004, a San Diego clothing manufacturer of the same name sued Spears for $10 million and banned her from using the trademark.
The tour was described as a "unique, mysterious hotel powered by an onyx stone, where guests who enter shine their own light into the gemstone and make their fantasies come to life.
[13] Spears also stated about the tour, "I would love my audience to walk out of the auditorium feeling like they had the most magical experience of their life.
Promotional campaigns included were animated e-mails targeted to two million people who fitted the audience description.
Vice president of music marketing and promotion Joe Armenia talked about the sponsorship, "There are not that many artists that appeal to every territory with an MTV channel, but Britney Spears is one of the select few.
[9] The show began with a skit where a flamboyant master of ceremonies welcomed spectators to the Onyx Hotel.
She entered standing on top of a small bus dressed in a black catsuit, where she performed "Toxic".
She took a break to talk to the audience, before going into "Boys", which featured the male dancers pushing her while she was standing in luggage carts.
[16] In the next section, there was a video interlude of Spears wearing a flowered-themed dress and entering the "Mystic Garden".
[20][21] The next section began with a video projection of two guards watching Spears in her room through security cameras.
[22] Spears appeared on a smaller stage wearing a white robe and performed "Touch of My Hand" in a transparent bathtub.
[16] During the performance, she took the robe off to reveal a nude body suit with crystals that resembled her "Toxic" music video outfit.
[20] After this, "Me Against the Music" (Rishi Rich's Desi Kulcha Remix) began and Spears appeared on stage wearing a red ensemble.
"[23][24] MTV UK highlighted the comparisons with early Madonna tours such as The Girlie Show and added that "[the show] is a theatrical extravaganza, complete with camp compere, sexy dancers, glitzy costumes and extravagant set pieces and its all fabulously raunchy".
[...] Perhaps even subsconsciously, the Onyx tour's most significant role may be foretelling a future in Broadway or film musicals".
[21] Chris Willman of Entertainment Weekly believed that "In Britney, Paul Verhoeven's fantastic notion of the showgirl as superstar has become incarnate.
The Onyx Hotel tour hardly counts as one, with its arbitrary mishmash of Madonna-esque sex-bomb skits and Cirque du Soleil surrealism".
[27] The Seattle Times's Pamela Sitt said it "was high on spectacle and low on substance, veering crazily from burlesque to fairy tale to peep show".
This made Spears the highest-grossing merchandise female artist since she began touring in 1999, with a total gross of more than $30 million.
She left the stage and returned shortly after wearing a white robe, apologizing to the audience for not being able to deliver the encore performance.
[32] On June 8, 2004, Spears was shooting the music video for "Outrageous" in Manhattan, when she fell and injured her left knee.
[35] She was taken immediately to a local hospital, where doctors performed an MRI scan and found floating cartilage.
[35] On February 4, 2005, Spears filed suit in New York State Supreme Court against eight insurance companies that denied her a reimbursement of $9.8 million.
Attorney Jonathan Stoler who defended Spears on the case said, "These are the same insurers who had provided her with policies on [several] tours and they had cleared her and were aware of the previous injury.
[12] She also wore a long black Roberto Cavalli dress, which was auctioned on eBay; proceeds went to the Britney Spears Foundation.
[39] The concert for Rock in Rio Lisboa festival in Lisbon, Portugal, was broadcast live on June 5, 2004.