But what SpongeBob didn’t know is that, when the string is pulled, a secret compartment opens and reveals something truly embarrassing for SpongeBob. Let's see what's inside. Patrick eventually shows SpongeBob what’s in the box: a piece of string. He then slides onto Patrick, grabbing the box] Good old secret box. He gets ready to reach for the box, but Patrick takes the box before SpongeBob could grab it.