It was safe to say you would miss him.

Over those eight months you had been in Camp Half-Blood, plus the two months you spent in the Wilderness School, you and Leo had become the best of friends. You'd kept up with him, making sure he was eating and getting fresh air during those months while he was building the Argo II. Now, all his hard work and labor was about to be put to use; he was leaving for the journey that would take him and the other six demigods all the way to Greece. He'd promised to Iris-Message you every night, but that didn't mean you'd miss him any less.

You'd held off on saying goodbye for a very long time. You'd already said it to Piper, Annabeth, and Jason, but not Leo. Now it was the morning before the four of them were leaving. You sat on top of a table in Bunker Nine as he fiddled with something, trying to find the right words to say goodbye.