Ex Machina, Vol. 6: Power Down is another excellent volume in Brian K. Vaughn's graphic novel series about an AU post-9/11 New York. As Mitch Hundred continues to tow the line between his past as a superhero and his present as Mayor of New York City, he's confronted by a stranger who seems to know what causes Mitch's powers. Although the hints about his "secret" continue to be annoying rather than tantalizing, the sharp left turn the long-term plot takes in this collection more than makes up for tiny squabbles I have with the series. ( )