and the human experiments conducted by Nazi physician Josef Mengele. The album was distributed by Geffen Records on October 7, 1986. However, due to the controversy, Reign in Blood did not appear on Geffen Records' release schedule. Although the album received virtually no radio airplay, it became the band's first to enter the Billboard 200, peaking at number 94, and the band's first album certified gold in the United States. Slayer embarked on the Reign in Pain world tour, with Overkill in the US from October to December 1986, and Malice in Europe in April and May 1987. They also played with other bands such as Agnostic Front, Testament, Metal Church, D.R.I., Dark Angel and Flotsam and Jetsam. The band was added as the opening act on W.A.S.P.'s US tour, but just one month into it, drummer Lombardo left the band: "I wasn't making any money. I figured if we were gonna be doing this professionally, on a major label, I wanted my rent and utilities paid." To continue with the tour, Slayer enlisted Tony Scaglione of Whiplash. However, Lombardo was convinced by his wife to return in 1987. At the insistence of Rubin, Slayer recorded a cover version of Iron Butterfly's "In-A-Gadda-Da-Vida" for the film Less than Zero. Although the band was not happy with the final product, Hanneman deeming it "a poor representation of Slayer" and King labeling it "a hunk of shit", it was one of their first songs to garner radio airplay. In late 1987, Slayer returned to the studio to record their fourth studio album. To contrast the speed of Reign in Blood, the band consciously decided to slow down the tempos, and incorporate more melodic singing. According to Hanneman, "We knew we couldn't top Reign in Blood, so we had to slow down. We knew whatever we did was gonna be compared to that album, and I remember we actually discussed slowing down. It was weird—we've never done that on an album, before or since." Released in July 1988, South of Heaven received mixed responses from both fans and critics, although it was Slayer's most commercially successful release at the time, debuting at number 57 on the Billboard 200, and their second album to receive gold certification in the United States. Press response to the album was mixed, with AllMusic citing the album as "disturbing and powerful", and Kim Nelly of Rolling Stone calling