Here is the full list of all 27 Thieves Gambit: The Curse of the Black Cat achievements.
Start a romance with Nick.
Become the world's most famous jewel thief.
Escape the palace.
Went in through the front door.
Start a romance with Rania.
Discover Nick's true identity.
Dance with Rania.
Charmed the Duke.
Steal the Black Cat.
Revealed Ludomir Ivankov.
Went in over the garden wall.
Investigate the palace.
Dance with Nick.
Recruited Nick.
Escape the city.
Recruit Le Roux.
Recruit Nora.
Recruit Rania.
Escape the Paris police.
Charmed the Duchess.
Charmed the heir.
Started a romance with Bouchard.
Went in disguised as a maintenance team.
Refused to join Bouchard.
Teamed up with Bouchard.
Double crossed Bouchard.
Succumb to the Curse of the Black Cat.