- "Luckily, there's always one guaranteed weak link in any security set up. The human heart."
- — Carl Johnson
Key to Her Heart is a mission in Grand Theft Auto: San Andreas given to protagonist Carl Johnson by Wu Zi Mu as part of plans to pull off a heist off Caligula's Palace from The Four Dragons Casino, located along The Strip in Las Venturas, San Andreas.
Carl has just returned from the Las Venturas City Planning Department with the blueprints of Caligula's Palace, which he and Woozie intend to burglarize. The next step in his plans involves providing his team access to Caligula's restricted areas by wooing and gaining the trust of one of the casino's croupiers, Millie Perkins. Carl takes Millie out on dates and slowly convinces her of his genuine affection. Eventually, she trusts him enough to let him use her key card for the heist, the plans for which Carl has intimated to her. He assures her that she will receive a generous cut of the purloined cash, and takes her security card back to The Four Dragons Casino in preparation for the next steps of the plan.
In order to complete the mission the player must:
- Get to Caligula's Palace casino
- The Croupier has a keycard and knows the code, follow her
- She's gone into the sex shop, follow her inside
- The Croupier is in here somewhere, find her
- Go and get a gimp suit
- Leave the shop and go after the Croupier
- The Croupier has left the shop. Follow her but remember not to get too close
- The gimp will be arriving shortly, wait around and make sure he doesn't make it to the Croupier's house
- Now that the gimp's out of the way go and ring the doorbell
The reward for completing the mission is an increase in respect. The mission Dam and Blast is unlocked. The player may now also take out Millie Perkins for dates. Also, the Gimp Suit will be delivered to Carl's wardrobe.
- Any vehicle you used to go to the Sex Shop will disappear and replaced by a parked Windsor upon exiting the shop.
- There is a glitch that may happen in the Mobile version where if Millie crashes into another person's car, the driver may pull her out of her Club and attempt to kill her. This event usually occurs near the Big Bananas store and if the NPC is not sniped dead quickly, the mission will fail as Millie will die.
- However, if Millie manages to kill the NPC before they do, Millie will stand in place and not drive to her house, pausing the Spook-O-Meter. If the player does arrive at their house, they can see a duplicate Club parked with the door open and Benny walking. If the player kills Benny and goes to Millie's house, the mission will end as normal, but the duplicate Club will vanish.
- A Love Fist poster can be seen when Carl and Woozie discuss their plans to rob Caligula's Palace.
- In the sex shop, there are two stationary NPCs, apparently browsing the items on the shelves. One is a pimp who can be seen around Hashbury, and the other is a vendor.