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