Here is the full list of all 27 Thieves Gambit: The Curse of the Black Cat achievements.
Recruit Rania.
Recruit Nora.
Recruit Le Roux.
Escape the city.
Recruited Nick.
Charmed the Duke.
Dance with Rania.
Investigate the palace.
Start a romance with Rania.
Went in over the garden wall.
Revealed Ludomir Ivankov.
Steal the Black Cat.
Escape the Paris police.
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 through the front door.
Went in disguised as a maintenance team.
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.