The Real Cost of Magic 

In most urban fantasy, magic is just another resource. 

You have a mana pool, a power meter, an energy reserve. Cast a spell, it drains a bit. Rest up, it refills. It’s video game logic applied to narrative: magic as fuel in a tank. 

It’s clean. It’s predictable. It’s useful as a narrative tool because each reader has a concept for the amount of fuel in the tank. 

Magic should cost something that matters 

In Past Mistakes, every use of magic has a price. Not “you get tired” or “you need to recharge.” Real prices. Prices you can’t recover from with a good night’s sleep. 

Emily’s grandmother’s amulet burned a pattern into her palm the first time she used it to fight a demon. The mark faded, but the cost was paid. The amulet channeled power through her body in a way human bodies aren’t designed to handle. 

When Raymond uses his velvet pouch to unlock doors magically, it drains something from him that isn’t a point meter that ticks back up every five minutes. As he puts it, the magic takes "what it needs from me". He doesn’t really know what that is, or how much of that he regains with time, or with exposure to others. He limits how often he uses it because he knows that it costs something intangible, and that his understanding of this is limited. 

When Emily performs exorcisms, she’s exposing herself to forces that can tear at her psyche. The more powerful the demon, the more it costs her to confront it. Not in energy. In changes to herself, in who she has to become to be able to do what she does. In exposure to different theologies that can exact a cost in return for their contribution to her battles. A cost not always neatly labelled or clearly communicated prior to purchase. 

This blends metaphorically with what soldiers go through - what they have to become to be able to do what they do.

The biggest cost: binding to Ahazu 

The central problem of Past Mistakes exists because Emily made a catastrophic mistake seven years before the book begins. 

She tried to summon a demon as part of a ritual with friends. None of them knew what they were doing. The ritual went wrong. People died. And Emily accidentally bound herself to Ahazu, a greater demon. 

Not “bonded with.” Bound. Trapped together. 

Ahazu can’t exist in the physical world the way he wants. Emily can’t get rid of him. They share a connection neither of them wanted, and it costs both of them constantly. 

For Emily, it means she’s never alone. There’s always something ancient and inhuman in the back of her mind, a manifestation of the mistake she made long ago.  

Something stirred deep inside me, coiling around the very fabric of my body and mind like a long-acquainted symbiote. Something almost a part of me and yet utterly alien. 

She can feel Ahazu’s presence, his attention, his reactions. Sometimes she can feel his emotions bleeding through into hers. Sometimes she can’t even tell the difference between her emotions and his. 

For Ahazu, it means imprisonment. He’s stuck inside a human who doesn’t want him there, unable to move freely, unable to exist on his own terms. His power is constrained by her limitations. He’s almost a god in his true form, and yet now he’s a passenger, trapped and near-powerless. 

Neither of them can break the binding. 

Choices with permanent consequences 

This is why magic in Past Mistakes isn’t just another tool in the protagonist’s arsenal. Every time Emily uses magic, every time she calls on Ahazu’s power, every time she performs an exorcism, she’s making a choice with consequences she can’t undo, and doesn't necessarily understand in advance. 

Does she use the amulet and risk burning herself again? Does she ask Ahazu for help and strengthen their connection? Does she push herself to exorcise a demon knowing it might break something inside her she can’t fix? 

These aren’t tactical decisions. They’re desperate gambles with permanent stakes. 

The demons Emily faces don’t play by video game rules either. They don’t have health bars. They don’t get weaker when you hit them enough times. They’re dangerous because they’re alien, unpredictable, operating from frameworks Emily doesn’t fully understand. 

Every confrontation is a problem she has to solve with incomplete information and tools that might cost her something irreplaceable. 

That’s the tension I wanted. Not “can she beat this enemy?” but “what will she have to sacrifice to survive this?” 

At the end of some of these battles, Emily can barely stand, and she’s fortunate to have found people who care enough to stitch her back together. 

Why this matters 

When magic costs nothing, it’s just spectacle. Flashy effects, cool powers, but no weight. 

When magic costs something real, every choice becomes meaningful. The reader has to weigh the cost along with the character. Should Emily do this? Is it worth it? What happens if she doesn’t? 

That’s the "mechanism" I wanted. Not someone with unlimited power learning to use it responsibly, but someone with limited, costly power trying to solve impossible problems without destroying herself in the process. 

Nick 

P.S. Next week: “Two to Tango,” the complete side story of how Emily and Raymond first met. Spoiler: it involves a possessed woman, a flying sofa, and mutual professional disdain.