Thirteenth Step is the second studio album by American rock band A Perfect Circle, released on September 16, 2003.

[6] He had recorded it with a female vocalist in mind, but upon Tool vocalist Maynard James Keenan hearing it and offering to sing for the material, the content was then quickly finalized upon adding Keenan's vocals and re-recording the drums with band member Josh Freese.

[9] As such, Howerdel would send work in progress instrumental he would create, and Keenan would write lyrics in between shows, a process they found to be efficient, but ultimately more difficult to balance than they initially expected.

[8] Keenan's work with Tool was not the only thing delaying work on the album, as progress was also hampered by other lineup changes, including guitarist Troy Van Leeuwen leaving to be a member of Queens of the Stone Age, and bassist Paz Lenchantin leaving to be a member of Zwan, leading to their contributions to the album being limited to only a few tracks.

[8] Keenan, in particular, wanted to move away from the general hard rock sound of Mer de Noms, feeling that taking that approach again would be "redundant".

And in the case of "The Outsider", it's sung from the perspective of a person who doesn't understand at all what their friend is going through, what their loved one is going through, and they think that it's more like a sprained ankle; they can just kind of walk it off.

Just prior to the 2004 Presidential Election, the band released Emotive, a collection of political war cover songs, which contained "Counting Bodies Like Sheep to the Rhythm of the War Drums", which was a reinterpretation of the track "Pet", and a remix album titled Amotion, which contained remixed versions of the tracks across their three albums, including the three singles from Thirteenth Step.

Media reception to Thirteenth Step was generally favorable; aggregating website Metacritic reported a rating of 74 percent based on 11 critical reviews.

[26] AllMusic strongly praised the album for having "the sound of a musical and lyrical maturity that normally doesn't occur until a band's third or fourth albums", and concluded that "Lyrically, musically, sonically, the Thirteenth Step is proof positive that mainstream rock has plenty of life and vision left in it.