Archaeologist Dr. Lamarck Mondrick has just returned to the United States after a two year expedition in Mongolia. He immediately calls for a press conference to announce his findings, which he considers of dire importance to the entire world. However, in the middle of his announcement, he suddenly collapses and dies.
Newspaper reporter Will Barbee, a former student and friend of Dr. Mondrick, was in attendance at the press conference. Though a coroner attributes his death to natural causes, Barbee begins to suspect foul play. Things become stranger during a dinner date with rival journalist April Bell, in which she claims to be a witch. He is initially skeptical of her claims of supernatural power, but he soon begins experiencing vivid dreams of transformation, magic, and murder.
When Barbee realizes his dreams bear a strong resemblance to the increasingly tragic events surrounding him, he finds himself questioning his sanity, and his role in the secret conflict in which he's become involved.
Darker Than You Think contains examples of:
- Abusive Parents: April's father. He regularly beat her because he believed she was another man's child. When her powers began to manifest, she was forced to use them to stop him from killing her and her mother.
- All Myths Are True: Homo lycanthropus is the basis for all the legends of sorcerers, vampires, werewolves, shapeshifters, etc. Williamson creates a sort of unified field theory of evil, attributing all the worst traits of human nature and dark events in history to the witch species and the taint of their genes in humanity.
- Big Bad: April herself.
- Bizarre Alien Senses: The witch species can sense probability, which they manipulate to influence events They can also detect the emanations of a material harmful to them, which one character speculates is radiation.
- Corrupt Corporate Executive: Preston Troy is a millionaire and owner of the Clarendon Star, a local newspaper. He's cheated on his wife with countless women, is heavily involved with the crooked city government, and uses his paper to produce biased propaganda in the hopes of getting an equally crooked friend elected Senator. He's also a loyal member of April's coven.
- Dark Messiah: The Child of Night, who both sides believe will lead the shapeshifters in reclaiming their lost empire. Multiple characters refer to this individual as a "black Messiah".
- Evil-Detecting Dog: Dogs are capable of sensing the presence of shapeshifters, even in their astral form. It's suggested ancient humans domesticated them specifically for this purpose.
- If It Bleeds, It Leads: According to Barbee, this is the philosophy by which Preston Troy runs the Clarendon Star. This makes him rather suspicious when his boss rejects a news story about Dr. Mondrick's mysterious death as "too sensational".
- Mage Species: The shapeshifters are frequently referred to as witches, and believed to be the inspiration for medieval stories of witchcraft. Though their abilities are treated as genetic, it's shown that practice and training are required for them to develop. April relates that her powers first manifested as a form of Sympathetic Magic.
- Our Vampires Are Different: Like vampires, the shapeshifters are vulnerable to sunlight, but only in their astral forms. It's revealed that ancient shapeshifters were buried with special weapons to keep them from rising from their graves. When Barbee's physical body is killed, his astral form is stated to be immortal, and April flat out calls him a vampire.
- Our Werebeasts Are Different: The shapeshifters (dubbed Homo lycanthropus by the Foundation) are believed to be the inspiration for myths and legends throughout the world involving humans changing into animals. Though the Latin name suggests werewolves, they appear to be capable of taking the form of any creature they can imagine (even creatures that have been extinct for millions of years). While transformed, they retain their human memories and motivations, though Barbee finds himself compelled to obey April's commands. Like werewolves in other works, they are weak against silver. Unlike most stories, the transformation is not to their physical body, but rather a mental projection of their consciousness (dubbed a "mind-web" by April) which takes the desired shape. For this reason, they can only take their beast form while their human body is unconscious. The Child of Night lacks this limitation, and is able to physically transform while fully awake.
- Tomato in the Mirror: Will Barbee is ultimately revealed to be the Child of Night whose identity he has been seeking throughout the story.
- Who You Gonna Call?: Dr. Mondrick's Humane Research Foundation appears to be an ordinary group of researchers, but was created to study and fight shapeshifters. All but one member of the Foundation is killed, but it is implied he may try to create another more secret organization.