For watch lovers, one of the most fascinating aspects of the Portugieser Tourbillon Mystère Rétrograde is the unusual presentation of the flying tourbillon, consisting of 82 parts, as a “12” that appears to come to life. After the 31st day of the month, the retrograde date display automatically jumps back to the 1st; in shorter months, the hand can be directly advanced using a rapid-advance system until it reverts to the 1st. The 7-day power reserve display indicates how much energy remains in the IWC-manufactured 51900 calibre. To mark the 75th anniversary of the Portugieser (Portuguese) watch family, IWC has given a timepiece swathed in mystery an additional touch of luxury. The arched-edge front glass endows the watch with a more classic, balanced appearance. The horns have also been ergonomically optimized to make the watch more comfortable to wear on a slimmer wrist. Another new feature is the exclusive alligator leather strap by Santoni. The reverse side of the watch with its see-through sapphire-glass back is also more attractive. The narrower and partly perforated rotor – now made of solid red gold – provides a generous view of the IWC-manufactured calibre, which also features blued screws. In the Portugieser Tourbillon Hand-Wound, the “whirlwind” – as the word tourbillon translates – turns at “9 o’clock” on the dial. The tourbillon rotates around its own axis once every 60 seconds to counteract the pull of gravity on any disequilibrium in the balance wheel that would adversely affect the watch’s rate and accuracy. The IWC-manufactured 98900-calibre movement with its intricately decorated nickel-silver three-quarter bridge can be admired through the transparent sapphire-glass back.