In a world where 1% of the population has gained mutant powers police procedure has changed forever. The characters are members of the Heightened Crime Investigation Unit that specializes in crimes involving the mutant community. If a crime was committed by a mutant, it's the Unit's work. If the crime was committed against a mutant, it's the Unit's work.
This game contains examples of:
- Capepunk: Think of it as CSI meets X-Men (and strictly "street-level" in power) and you'll get the picture.
- Extraordinary World, Ordinary Problems: 1% (and rising) of the world population getting powers hasn't created superheroes. It's only made street crime somewhat more... odd.
- Fantastic Legal Weirdness: This game showcases various elements of how law enforcement had to change to accommodate superpowers appearing, such as an investigation having to take into account whether or not someone was being mind-controlled at the moment of their committing the crime.
- Fantastic Racism: Subverted. After ten years, the appearance of superpowers was treated like any other type of minority definition — which means that, yes, stuff like mistreatment because of powers occurs but side-effects like Super Supremacist, Muggle Power, the harsher parts of Mutant Draft Board and even wanting to be a true-blue Superhero are all treated equally as the acts of deranged men.
- Fantastic Science: In a world where people with superpowers is a rising minority and, after scientific analysis has discovered the intricacies of how Magic A Is Magic A (including facts such as Power at a Price, Elemental Baggage, how Neurodiversity Is Supernatural as a potential side-effect of certain powers, and so on), the result is that forensic science has evolved and is now possible to perform such things as "gunshot residue" testing for Hand Blast powers, determining if Psychic-Assisted Suicide has happened via X-raying the victim's brain, criminal profiling based on knowledge of a person's powers, and so on.
- Mass Empowering Event: Ten years ago in the setting, a flu-like illness labeled as "the Ghost Plague" spread across the planet. It killed millions, it was incurable, and it stopped and disappeared as mysteriously as it showed up; leading some to suggest it was a biological weapon and not a plague. Several months later, however, the first superpowers started to manifest all over the world and in people from all walks of life. This became known as the Sudden Mutation Event.
- Mutant Draft Board: Subverted. Power registration is a part of life, but it exists because of the acknowledged risk of certain powers to be dangerous to people (ex. Hand Blasts treated like firearms) or to people's securities (ex. someone using X-Ray vision for sexual harassment).
- Neurodiversity Is Supernatural: A detail of how Magic A Is Magic A is that a side-effect of how powers manifest on a person's biology is that their mind molds the power and the power molds their mind. As an example, mutant with healing and regeneration powers have a significant chance of developing a messiah complex, due to their ability to heal people and ignore being hurt themselves, or someone with the ability to read minds and alter memories having an increased risk of megalomania due to being able to control and predict the memories of those around them. The second edition opted to largely remove this, largely due to Unfortunate Implications vis-a-vis mental health.
- Shout-Out: The game's name is an obvious riff on Hill Street Blues.
- Superpower Lottery: Averted. Power design in this game means that a mutant will be either pretty powerful on just one ability (like having a very powerful Hand Blast) or be so-so powerful on various abilities. Furthermore, most powers have their downside that becomes stronger the more the power is used (such as for example becoming increasingly autistic if you have force field abilities) and some powers are flat-out incompatible with each other (which means that finding someone being affected by two of them is automatic evidence that there was more than one perpetrator).
- Superhero Prevalence Stages: A fairly realistic mid-to-late level: people with superpowers exist and the world had to change to accommodate them, but overall wanting to be a "superhero" is seen as an act of insanity because powers are not that Earth-shattering.
- 20 Minutes into the Future: The "current day" of the setting is ten years after the manifestation of mutants.
- Unbelievable Source Plot: Subverted. Not only are superpowers accepted (so it's not "unbelievable" if it's a result of them), but it's required by law that investigators provide more evidence for their case than just the hearsay of a mind-reader.