Or et machine... et temps ?

Missing, extremely new, or very obvious to obtain.

This achievement has no cultural references in the English and Chinese versions. It is likely specific to the game. It's a reference to Simulated Universe: Gold and Gears, which uncovers the mysteries of the events during the Mechanical Emperor's Wars and before #27 Rubert's death. "Gold and gear... Clock?" has the Trailblazer uncover the mystery behind Clockie turning rocks into gold. The achievement's title could also be taken literally with Gold as the rocks-turned-gold, Gear as the puzzles we solve to uncover the mystery, and Clock as Clockie.