All Times possible - Gordon Eklund, Gordon R. Dickson

A story about trying to pull the strings of history. I regret my vague knowledge of Marxist historical theory, since I think that would have helped me understand the author's intent; nonetheless, it struck me as quite a good work of alternate history, more thoughtful than most entries in this often-trivial genre; narrated with skill, too, from multiple points of view. No longer than it needed to be.