Dr. Helen Magnus suspects the work of an "abnormal" in a bizarre jewelry robbery that results in a fatal shooting. The thieves take only gold, leaving behind easily accessible diamonds, silver and precious gems. In addition to the selective choice of loot, the culprits make a mysterious getaway that baffles the police. It seems they were able to disappear from a room that had no escape, short of a tiny duct through which no one could possibly fit.
The robbery and inexplicable getaway reminds Will of a case he worked on years before with the FBI, but could never solve. Magnus sheds new light on both cases when she suggests that this may prove the urban legend of the "folding man," a sub-culture of humans able to collapse their skeletons to fit through impossibly small spaces.
Although skeptical of the existence of a folding man, Will is beginning to believe that with Magnus and the Sanctuary, anything is possible.
Comparing Will's old FBI case with the recent robbery leads the team to Oliver Braithwaite, a drifter in Old City who might have the answers they need to prove that folding men are no myth. What he reveals confirms their suspicions, but also throws them into a drug trafficking conspiracy that combines murder and deceit in a twisted criminal plot. It also teaches Will some lessons in solving crimes the Sanctuary way.