Dark Matter
A propulsive sci-fi thriller in which a Chicago physicist is kidnapped and forced to navigate parallel realities to reclaim his family. Violence, gun use, strong language, drug use (plot-central), and brief sexual content make this solidly adult reading.
Chapters to know about
Jason is confronted at gunpoint, forced to drive to an abandoned warehouse, then injected with a drug against his will and knocked unconscious -- sets the book's baseline of threat and physical peril.
Forced injection and non-consensual confinement in a high-security laboratory begin here and are revisited throughout the early chapters.
An alternate-world scenario depicts frozen corpses and environmental devastation; a separate alternate world is ravaged by a hemorrhagic viral epidemic with graphic descriptions of the infected.