The Hawke's Bay Add-on for HITMAN 2 has 7 achievements worth 150 gamerscore.
Eliminate Reynard while Orson showers, from the roof of the panic room, and with a pillow.
Trawl the beach.
Complete all Nightcall Challenges.
Complete Nightcall on Master Difficulty.
Select a Starting Location and use an Agency Pickup to smuggle an item into Hawke's Bay.
Reach Hawke's Bay Mastery Level 5.