In Italy, the characters discovered that though the main Brotherhood is based in Rome, they also maintain a Milanese chapter, and it was this faction that Malcolm Quarrie joined.

• Other known members of the Milanese chapter included Thomas Villiers, Roberto Anzalone and Giuseppe Colombo, all of whom were later discovered to be the secret backers of Quarrie's 'Pilgrimage of Grace'.

• In their conversation with Villiers, he described the beliefs of the Brotherhood as being based on the idea that Christianity is a corrupted version of the truth of Hastur. The strange theology of the Brothers has byakhee as angels and says that the Christian Trinity is an echo of the trinity of Hastur (the father), the King in Yellow (the son) and the Stranger, or Prophet (the holy ghost).
• The Brothers seem to believe that the coming of the King in Yellow to Earth is the truth behind the Christian idea of the second coming of Jesus.
• According to Umberto, the Brotherhood are secretly led by a group of immortals from the ancient land of Valusia whose overall aim is to bring Hastur to Earth and to rule in the name of their 'Living God'. Though he seems quite certain of this, he has no actual evidence to support this claim.

Although not directly in conflict with the Brotherhood of the Yellow Sign, the party encountered this cult and its influence several times during the campaign:

• The Rome chapter of the Brotherhood sent an assassin after the former Vatican investigator, Umberto, after becoming worried about his activities. The assassin, when captured by Nathaniel Browne, was carrying an ornate stiletto bearing The Yellow Sign.
• Aleister Crowley suggested that Malcolm Quarrie may have gone to Italy to see “Il Fratelli di Signo Giallo”, an artistic circle based in Rome that meets once a year to perform a single private performance of a particular play. Crowley stated that he dislikes drama, and as such has no interest in “The King in Yellow”.