"I know. You don't know them like I do. Just..." Somehow Alec manages to not make a face or indicate any sort of disgust in his voice. "If Gruber gives you a pebble and asks you to keep it safe? Don't."

To explain further because Phoenix does deserve the explanation, "The Fool gave him the pebble - it has a bit of his shadow attached - and told him to keep it safe; don't let anyone know about it. He might give it to you. If you have it, then the Thief can find it because it's supposed to be a secret. If he can find it, he can find you..."

There's really no reason for him to finish that sentence. He just pulls Phoenix in for a worried hug.