Masereel's work, as one of Will Eisner's inspirations, is an ancestor of the modern graphic novel. That historical insight is a freebie, though. Reading this slim book offers many rewards of much more direct sorts.
It's not a graphic novel itself, no matter what some have said about it. Instead of a novel's narrative coherence, this presents a sequence of still images. They relate to each other only loosely and conceptually, not in causal flow. This criticism applies only to how Masereel's work is presented, however, and not to the work itself. That is exceptional.
Woodcut may look crude, if your eye isn't attuned to it. Edges are hard; delicacy arises from the subject matter and composition, not from the medium. That works well in this case, since Masereel uses it to document the hard parts of city life between the two world wars. He shows love freely given, but also physical love for hire or taken by force. There is death, violence, and military hardware in the streets. Masereel shows both sides of everything, though: medical students harvest life for others from a woman's cadaver, and a steel mill's torrent of fire reminds the reader of how society's tools and materials are formed.
Masereel's visual style tends toward the primitive, despite the city sophistication of his subjects. It works. His primitive lines emphasize the primitive urges of life, love, control, and violence. He fills his visual field with detail. Even though woodcut is a medium of contrasts, many of these prints tend toward a uniform texture and "gray." That sometimes makes it hard to focus on the central points of an image. It also conveys that very urban sense of closeness and distraction, the feeling that everything everywhere is competing for attention, and confusion about what really needs the attention.
Dover has recently brought this and similar work (including Lynd Ward's) back into print after decades of obscurity. Perhaps the copyright limit expired and the work has fallen into the public domain. Whatever the reason, it has fallen back into public awareness, too, and I'm glad of it.