Introduced in 2004, the IWC Portugieser Tourbillon Mystère featured a contemporary 44mm diameter case and was released as a limited edition of 250 examples. Equipped with a tourbillon escapement at 12 o’clock, the complicated mechanism was first developed to offset the gravitational error inevitable in an oscillating system with a balance and spring by distributing error evenly over a single plane. The solution was to place the balance, pallets and escape wheel in a tiny cage that would then rotate around its own axis once every minute.

Featuring a 7-day power reserve, the ref. 5042 is a true revelation and a testament of the firm’s technical prowess to traditional watchmaking. Numbered 236 of a limited edition of 250 pieces, the present example offered in attractive overall condition is also accompanied by its original numbered wooden fitted presentation box.