First Storm by Lucas Flint

Waking up on his day off, Alex Fry (Beams) sees an impenetrable magical barrier in the sky over his hometown of Golden City.

It turns out that the barrier was constructed by the Zero Knight called Mirar, who has come to Golden City to avenge the death of his fellow Zero Knight from the previous book. To that end, Mirar has trapped every man, woman, and child in the city, and even worse, has set a 24-hour-deadline, at the end of which everyone inside the barrier will die.

To save his friends, family, and neighbors, Beams must ally with an old enemy of his, whose magical knowledge is the key to lifting the barrier. Yet Mirar leaves nothing to chance, sending his deadliest servants after Beams to ensure he cannot save the city.

With time rapidly running out, will Beams be able to save himself, much less the whole city and everyone within it?