"Get back with something useful." This is when Cole and Gavin are creating something. "It will be fun. I promise." They are only making something that is going to be "fun" which may not be the case. What can be something fun? What are they going to do? What ideas are they going to come up with?
I don't want this to be a bad plan because I don't think they are thinking about the consequences. What are some ideas they are going to come up with? Maybe something not so bad. But it also may only be fun for Cole and Gavin. No one knows...