The blow to Serenity from leaving the ley line seemed stronger than before, but when he checked his Status, it looked like he’d lost about the same amount of Mana and Essence as when he first arrived on Earth. It probably felt worse because he’d had a short reprieve from the enervation of continually losing magic.

They were quiet as they piled back into Rissa’s car, but as she tightened her seat belt, Rissa turned to her father. “Do we tell Mom?”

Russ closed his door and buckled his own seat belt as he thought. The silence stretched past when Rissa started the car, but eventually he spoke. “No. She’d tell Red, and Red will tell anyone who’ll listen to her. That’s not that many people, but these days she might be believed instead of brushed off.”

“Is it something we need to keep secret?” Rissa seemed a bit tentative as she drove back to her home, and Serenity had to remind himself that she’d been avoiding leaving the house. Going out on even a small trip like this was an important step.

“Until I can figure out why Auspex sounds so familiar, yes.” Russ stared at the city streets; Serenity couldn’t see them without rolling down his window. “I think I can find out if I’m careful, but it may take a few days.”

Rissa nodded. “Mom should understand that.”

“Hah! Your mother doesn’t have an understanding bone in her body! No, she’ll blame me for it, I’ll tell her it’s my job to keep both of you safe, and she’ll walk off in a huff. I may have to sleep on the couch for a couple of days, but she’ll get over it.” Russ sounded amused, almost like he was fond of his wife’s reaction.

Serenity couldn’t help but ask. “Is that common?” He had to turn to see Russ in the back seat.

Russ nodded. “Yeah. She’s worse than Rissa is about reacting before thinking. Better about letting things go, though. Rissa will hold a grudge ‘til the cows come home.”

“HEY.” Rissa somehow seemed amused and offended at the same time.

Serenity had the feeling this was a long-running gag in the family.

There was a squawking noise, like metal on metal. Serenity thought it was the garage door, which meant they were probably home.

Not being able to see through glass sucked.

Phoebe met the three of them inside the house and insisted that Serenity put his disguise back on. He wasn’t thrilled about it - he could already feel his wings ache at the prospect of being firmly held in place for hours - but he didn’t argue. She wouldn’t say whether she was being cautious or if she’d had a premonition.

Serenity suspected she wasn’t certain which it was. He’d talked to Rissa about the weak end of her foresight; it seemed like years ago but was really only a month or so. She’d told him that it could be hard to tell a weak premonition from an ordinary concern or hope.

Rissa did a lot of her stock trading on similar hunches, and while she was far more accurate than most traders, her success wasn’t perfect. She’d admitted that it could have been if she only went with her strong hunches, but she deliberately didn’t do that; perfect market prediction was too likely to be noticed, and she didn’t need to be investigated for insider trading. She still spent a lot of time doing research; after all, the more she knew, the easier it was to get good insights.

Serenity didn’t really understand their foreseeing, but if it followed the normal rules of magic, that made sense. It was the same idea as the divination he was doing - the amount of power required was related to the amount of work the magic had to do, and having a good starting point would lower the required magic a lot.

The search for the stolen whatever-it-was didn’t quite go as planned.

The very beginning did; Serenity started the tracking spell, then walked down the driveway and checked which way the trail went while Rissa and her parents piled into the car, then picked him up. Serenity rolled down his window; while he could follow the spell without being able to “see” it, it was more comfortable to be able to see the world go by.

Moments after that, they went past the point Serenity’s spell had been able to trace and had to go back.

Serenity had built the spell for efficient mana use, rather than speed. It would only run while the current tracking point was within his aura, since that was only slightly more expensive than touch range, and it moved forward slower than the car, even in the subdivision. They spent some time trying to go slow enough to not outrun the spell, and eventually Rissa was able to keep the car in a range where they could move along as the spell tracked.

“This isn’t going to work. We can go this slow here, since no one’s around, but it won’t work elsewhere.” Rissa’s eyes were spending more time looking at the rearview mirror than the way forward, and Serenity realized she was actually nervous. They weren’t moving very quickly.

“How fast are we going?” Serenity was in the passenger seat, but he couldn’t read the speedometer.

“Mm,” Rissa took a moment to watch the gauge as they rolled forward steadily. “About eight? That seems to be about as fast as we can go and not have you lose it sometimes.”

“Hm.” Serenity was pretty sure he could run that fast for a long time, but he wasn’t sure anyone else would be able to keep up with him - at first, sure, but they didn’t know how far it was. “We could jog I guess, slow down to a walk when needed?”

“Can you boost the spell to be faster?” Russ interjected from the back seat. “I’m sure they were in a vehicle to take that much stuff, so it’s not like we need to worry about off-roading.”

“Not without building a new spell. Too many downsides; it’d risk overrunning what it was following and having to find it, and it’d damage the trace it’s trying to follow; might make it impossible to find again if something goes wrong. I’d rather not risk that. With a new spell…” Serenity stopped to think about what a different spell would need to work.

Arcane affinity, obviously, and spacetime; he’d used both of those for this. Even if his arcane affinity no longer showed on his Status, Serenity could tell it was very high; he was seeing less loss than he’d expected. It was proving much easier to trace the magical residue than he’d expected, as well; he’d at least half-expected his current spell to damage the trace, and it really wasn’t.

The current spell was highly optimized, with a ‘mana feed’ from his aura into a governing structure with several closely-fitted pieces. The simplest in concept was an arcane ‘box’, a storage area slightly out of time, where he held a tiny bit of what he was trying to find. There were ways to do it with simply the Arcane affinity, but using Time as well meant that the trace wouldn’t degrade easily and made it more likely that it would continue to match even if the artifact was somehow magically changed.

He’d considered trying to use essence as well, but the spell didn’t feel right for it. Serenity knew better than to ignore that sort of feeling, especially with what little he knew about what essence was good for backing up the feeling. He’d ended up going with what he thought of as a conventional spell.

Serenity thought of it as a ‘simple detect-and-follow spell’, but no one on Earth (other than possibly a few deities and one particular Sterath boogeyman) could have built it at all, and of those very few could have built it from memory. Even then, most would have needed to use an aid to cast it; skill at casting spells and skill at making them didn’t often line up, but Serenity had spent literal millenia practicing both.

Most spell creators would build a custom spell that did exactly what they needed every time. There were advantages to that route; they didn’t have to have a huge library of pieces or figure out how to fit the pieces together. It also generally made the spellforms a little simpler and more contiguous, which was very important when trying to create a chant-and-gesture-and-component method to create the spellform. On top of that, having all the parts pulling together could reduce the cost and increase the speed a little - not much, but even a little can matter.

Serenity had long since abandoned that method as wasteful due to its downsides - yes, it was easier to tune every spell, but every spell had to be individually built and tuned (and in his opinion, debugged). By building his spells the way a programmer would - with pieces he’d already fully tested - he could build exactly the spell he needed for a situation instead of using a more general spell he’d memorized.

To some extent, that was preference rather than an actual advantage; many of the prebuilt spells were very flexible, after all. Of course, to achieve that flexibility, they’d given up the primary advantage of their own method - the perfect tailoring. Serenity considered the fact that most mages almost exclusively used the more flexible prebuilt spells that came in as less efficient than his own to be proof that the custom method wasn’t worth it in almost all circumstances.

He certainly wasn’t the only person to use his preferred method of spell creation, but over time he’d become one of the best.

Serenity expected a lot of other Earth mages to follow his model when they started making spells, even though he wasn’t yet explicitly teaching it. He wasn’t anywhere near the best programmer out there, and it wasn’t only programmers that built from preassembled components, after all. Anyone who’d ever put together a piece of furniture had done the same thing, even if they didn’t realize it. No, the method of thinking was very, very common on Earth.

This spell was, like almost every spell Serenity made, composed of a number of pieces. The piece that was easiest to build - because it was in every spell - was the mana feed and outer wrapping. They were technically two separate modules, but because every spell needed them, Serenity had integrated each of the options over the years to the point where he didn’t even think of them as separate.

The next piece was the spatially-tied resonance block that let him know where the spell was within his aura. It had a companion that used the same spatial concept to ‘anchor’ the spell in place temporarily if it lost power and ran outside his aura. Without that, he’d have needed to recast the spell, including going to get the residue imprint, each time they left the trail. It was essentially pure spacetime, with only the arcane ‘hook’ to the rest of the spell. Working with a single affinity was always easier (even if Arcane was always needed to tie a whole spell together).

The next module was SpaceTime and Arcane again, and it was the only one he’d needed to extensively modify for this spell. The reason for the changes wasn’t really what he was trying to do; it was the fact that he had the SpaceTime affinity instead of Space and Time. He could still treat them as more or less separate most of the time, but for this module that was a negative, not a positive, so he’d rearranged it to cut a lot of now-obsolete logic. He could manage the module with two affinities now instead of three, and that made it much simpler.

The module was designed to detect the ‘most recent’ residue near the sensor’s current location. It required congruence in space but not time; he’d needed to make that decision when he plugged in his spacetime affinity instead of space and time separately. This way, it would ‘jump’ to the newest available line, even over a short distance.

While there had been something like that in the original spell, it had needed to call another module to determine the time-properties of a nearby detected trace. With spacetime, detecting the trace gave him both the time and space information innately. The new module was much simpler and more compact - and more importantly, it was also faster to make the decision and had a lower mana cost. Having the right affinity to do something was a huge bonus.

It was the core of the divination spell, really; all of the other pieces were bits that could be used in other spells, but this one was pure divination. It was also one of the few pieces that could nearly stand on its own as its own spell. It’d be a pain to manage and the object being searched for would have to be very close or the mana cost would be crippling, but it was as close to being a spell as any module he used.

There was simple glue logic tying the modules together; all it really had to do was manage the power and information flows, so it didn’t really take up much of the spellform. A few bells and whistles to do things like alert him to the spell’s status through his aura; those were normal and easy enough, he had space for them in the outer wrapper module.

That was all there was to it, really; a very simple spell.