The first three slices of a Faraday spectrum cube of a Hammurabi simulation and the associated LOS magnetic field strength. Each pair shows a frame at a different Galactic latitude. Top: a grey scale image of polarized intensity (in arbitrary units) as a function of Faraday depth and Galactic longitude. Bottom: the LOS magnetic field strength as a function of LOS distance (in pc) and Galactic longitude. The scale has been compressed to highlight regions with opposite polarity. Black indicates positive magnetic field strengths and white negative. The colored area is where B₃ ≈ 0 (appears as grey scale in text version).