For generations, writers have been fascinated with “what if” fiction. They’re enthralled by the concept of a world completely different than the one we know, transformed by a single change. What if the Germans had won World War II? What if there were life on other planets? What if people could swap souls or turn into animals? It’s ripe territory, and it’s territory Michael Chabon ably explores in his latest novel, The Yiddish Policemen's Union.

In the book, Chabon imagines that Jewish refugees and their descendents have flocked to a corner of Alaska in the wake of the Holocaust and the collapse of Israel. The Federal District of Sitka, where the colony exists, is set to revert to Alaskan control, and many in the district fear they will become displaced. It’s an interesting set-up, but for Chabon it’s just the backdrop for a fairly traditional noir murder mystery.

Sitka detective Meyer Landsman, a once-promising lawman with a broken marriage, troubled career and major drinking problem, discovers that someone has been murdered in the cheap hotel where he lives. Despite ever-growing obstacles, he struggles to get to the bottom of the case. As he delves deeper, he finds that the man in his hotel has a shocking connection to his own life and misfortunes.

Chabon does a wonderful job of creating a real alternate universe in Sitka and gets all the noir details right, too: the broken man; the good woman who still loves him; the loyal sidekick; the many, many shady supporting characters who may or may not be trying to help him. He also has a way with tiny details (for instance, at one point he mentions that the Sitka refugees are known as the “frozen chosen”).

“Union” can be enjoyed on many levels. It’s a compelling story of a world that might have been, but it’s also a vastly entertaining mystery.