It was Nick's idea, for Alex and Karl to do something harder for their shop project.  

Well, that's not exactly fair. Alex and Karl agreed to it. In their defense, it seemed like a good plan! A harder project, sure, but in-affinity for Karl, arguably in-affinity for Alex--the divination involved is mostly short-range, but he can argue it--and Nick's an artificing track senior, and he said I'll help, and he said this could be what puts Alex on the map, if you two do a good job, maybe this could be what gets him a spot in the alliance, it's time you proved yourself, and so they had agreed to make a more ambitious artifact than was necessary for their group assignment. It would be useful, too-- a shield from mals that notices not just where they are but where they will be, that goes up a second before they appear instead of a second after, is the sort of thing that saves lives.

It seemed a bit less like a good plan with every time Alex and Karl ended up working in shop alone, trying to get it done before the due date. Nick's good for his word, and he's with them almost half the time, but he's a senior, he's got his own homework, and he and George and the rest of Tampa's seniors have started training for graduation. But by the time Alex has realized hey, maybe this isn't the best idea, he's committed, they're over halfway done, and this, this could be his chance. He needs this. 

Nick is, at least, with them when Karl opens the wrong cupboard and mals start pouring out, going for his head. Nick moves fast--he's not as good at fighting as Clay, but he's still leaps and bounds better than any of the rest of them, by a lot--and his whip is all artifice, crackling with the sort of fire that doesn't go out right away when the sprinkler system turns on (maybe the same sort of fire that one of the library shelves had still been burning with when-- no, Alex, focus--), cutting a line through the mals until the air smells of charred flesh-- and then Alex starts chanting, suddenly incredibly aware of how slow his reflexes are and of how close the mals are getting to him--

Nick has a sword, too, the one they all make dick jokes about, and he's dual-wielding now, and Alex is still chanting, and he can't even see Karl at first under the mals but then he can, bits and pieces, his clothes first, all oversaturated colors made dim by three years of wear, and then a bit of his hair, and then more, and then more--

And at last they're all gone, and Karl's bloody and they're all hyperventilating but this is better than not breathing at all, and Nick loops his arm around Karl and walks him home.