What are devs supposed to do in dead time when they are waiting around for a peer to do a peer review?

You can't really start another story on the side as that would be denying another team member who isn't waiting around the ability to start the story for real. Straddling stories is bad. I've never seen that in any of the "agile" places I've worked. Man I hate the peer review thing. I'm glad that's not going on where I work now. I think it's a trapping of ghetto hole-in-the-wall startups which don't want to spend money on a testing team. (or maybe they want to spend the money but can't)