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