History teachers and school librarians sit naturally in a zone of mutual benefit, and this creates opportunities for truly useful collaboration. Everyone is supposed to be collaborating these days, partly because of research that shows it can produce better outcomes and partly because it’s associated with virtues like niceness and inclusion. Yet we’ve all known situations where collaborating just takes twice as long to achieve the same result. It is only when two people sit naturally in a ‘zone of mutual benefit’ that collaboration does live up to the hype. It helps both to achieve their aims far better than they could alone, and it’s more fun along the way.