I reckon there should be this mutable very near history and the 'now' and then a separate list for what characters would like to happen and then there is a list of entries for the fixed history - too late to change. That bit should be the one that reads like a book. All the characters chatter on the now and occasionally change the near past. They also need to maintain the future wish list from very near future which is quite clear to the far flung when it all gets very fuzzy.