After the 31st day of the month, the retrograde date display of the Portugieser Tourbillon Mystère Rétrograde 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. For watch lovers, one of the most fascinating aspects of this model is the unusual presentation of the flying tourbillon, consisting of 82 parts, as a “12” that appears to come to life. 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 movement with its intricately decorated nickel-silver three-quarter bridge can be admired through the transparent sapphire-glass back. The Portugieser Tourbillon Mystère Rétrograde in 18-carat red gold with a slate-coloured dial comes with a dark brown alligator leather strap from the House of Santoni.