Live pricing is coming soon. Get notified when it is available for this reference.
Movement tier: unclassified
Large case: suits wrists 7 in+ (18 cm+)
43 mm case. A bold, statement-size wear. Best suited to larger wrists where the case sits flush.
Not yet rated
Community + OSINT signals haven’t landed for this reference yet. We don’t publish a rating against zero signal: the number would mean nothing. Editorial body + caliber + market value still surface above; ratings appear once the signal corpus does.
Search pre-owned listings
Authentication
Mystery seconds must move while the movement is running; non-moving seconds with a running movement means the mystery mechanism has failed.
Known issues in the market
- The mystery seconds drive is the most service-sensitive part of Cal. ML187; any ML187 with non-moving seconds while the movement runs requires specialist service.
- The off-axis transmission driving the mystery seconds is delicate and should only be serviced by specialists familiar with the caliber.
| Area | What to check | What is correct | Red flag |
|---|---|---|---|
| dial | Mystery seconds function | Seconds hand moves continuously while movement is running; floating appearance with no visible connection | Non-moving seconds with movement running; mystery mechanism failure |
| caseback | Cal. ML187 architecture | ML187 in-house movement with mystery seconds transmission architecture visible | Non-in-house movement; movement swap |
| dial | Dial condition | Dial surface pristine; mystery seconds hand not touching dial surface | Mystery seconds hand touching dial; bent hand or dial deformation |
Common legitimate replacements
- Leather strap; Maurice Lacroix OEM.
- Crystal; sapphire standard.
Expert resources: Maurice Lacroix Masterpiece Seconde Mysterieuse documentation; specialist service only for mystery mechanism.
Authentication guide
Last reviewed June 2026
The Masterpiece Seconde Mystérieuse uses the ML187 caliber; the seconds hand appears to float without a visible connection to the movement, which is the defining authentication anchor.





