First: If you have lethal or brittle poisons that you can add to your inventory during the planning phase, or if you manage a tasting room level as a server, this will save you time. Don’t worry if you can’t do that either, we’re looking at card options.
First, follow the path below where Diana starts on the top floor. There will be two gauchos. Take them outside, steal one of their masks and go down to find a poisonous flower next to the cactus.
If you want to try to overcome the Hold My Hair challenge, you can leave the flower as it is. If you want to take on the challenge of tastelessness, you will have to take this flower to the Vineyard Barn and put it into scientific equipment to turn it into a deadly poison.
Then you need a screwdriver. Meet me at the entrance to the basement. On the left side, there is a barrel with a screwdriver that comes out and can be grabbed.
You must now enter the barrel room and descend the passage on the right side of the room. Use a screwdriver to remove one of the metal plates so you can enter the wine cooler. There will be two people here rushing for help when they see you. Work with the console next to one of the glass doors to activate the black frost and remove them both. There are three different kinds of wine on the three tables of the fridge. You can take on the challenge of estate wines one by one, but all you need is a Pinot Noir on the right.
Now that you have Pinot Noir, you’ll need a service mask if you haven’t already started it. The easiest way is to go to the tasting room. There is a side room where you can blow the fuses and force one of the servers to take cover.
Now you are ready to serve Vidal and Diana. You can drop off the pinot noirs at the bar in the tasting room and wait. If you wait a long time and they don’t come, you can find them and convince Diana that she needs a drink by approaching the waiter. It worked for us, but we can’t say definitively if it was because we were in disguise or if it was pure luck that she said it as we approached.
When they arrive, press the on-screen button to serve Vidal wine as a waiter. Move the camera to show the empty jar and you can put the poison inside. They’re in a waiter’s jacket, so putting something in the jar isn’t suspicious. Diane is going to have another wine at the bar, so don’t worry about poisoning her. Press Vidal’s button to make it work, and he’ll drink, giving you a challenge. Make sure you put the poison in before you serve it to him.
If you give him a lethal poison, Vidal will drop dead. If you sneak the poison in, it goes through the living room and bathrooms. Chase her around and drown her when she pukes in the toilet.