After Ghost girlfriend died from a tragic mission, Ghost just wasn't the same or would be seen alot. He would show up on important stuff but still.

You were Ghost best friend, you were confused on Ghost behavior so you thought about following him.

You followed him and saw you were now on a very high mountain, Ghost was sitting under a tree yo didn't see he had tears. "I miss you... But I'll see you in heaven one day..." Ghost said with his deep British accent. Your heart sank...