Everyone in Vaelthir knows the phoenixes. They sit in high roosts on the old bell towers and the university spires, and they have been part of the skyline for as long as anyone alive can remember. Across the city it is phoenixes, not lanterns, that light the streets, perched on iron stands at the corners and along the walks, though their great roosts cluster thickest in the University square, where they sit so close together that the dark never quite settles. However, these staples of Vaelthir life are in trouble. The birds have not burned in a lifetime, not one has taken the fire since the Silence began. Because of this, I have spent a month with the people who study these birds, and I have come away realizing that our ecosystem and city are in deep trouble.

Start with what a phoenix is meant to do, the fire is not the bird’s death. A healthy phoenix burns on a rhythm, ash to fledgling in a matter of days, and in the old times the roosts lit in their turn often enough that the earliest Vaelthir calendars marked burnings the way we now mark months of the year. None of that has happened here in a very long time. The roosts are full, and the birds in them are old, their feathers are greying, and not a single one has taken the fire since the season the Silence came down. We have called them lucky, but the naturalists I spoke with have a different word. They call them overdue.

The naturalists I spoke to say they found accounts of what becomes of a phoenix that misses its cycle, that is held from its small renewal for too long. A phoenix kept too long from the ordinary burning does not go gently. It goes all at once and enormously, in what the old texts call a supernova, a burning so far beyond a rebirth that it is not a rebirth at all. It is a catastrophe. It takes the roost, and a good deal of what stands around it, and it is remembered in those records as an ecological disaster rather than a miracle. Worse still, the bird that goes supernova does not resurrect the way an ordinary phoenix comes back. Where a healthy burning returns a fledgling within the week, a supernova leaves ash that takes years to stir, sometimes generations. The cycle is broken and takes a long time to heal.

One overdue phoenix would be a hazard worth a notice on the aviary door. Vaelthir has thousands of them, and by some counts more than that, and they have all been waiting the same length of time. Birds that share a roost and a rhythm tend, historically, to go together. A single supernova over the city would be a grievous thing. The roosts going up as one is what keeps the scientists who study this up at night.

For two years now a lab led by Professor Sabine Orrery, working out of the University aviary at the edge of the square, has been trying to coax a single old phoenix into an ordinary, controlled burning, under conditions where a normal rebirth could happen safely. They hope that if they can get the right conditions to cause a rebirth cycle to happen they can send phoenixes into supernova one at a time and save the city. They have tried warmth. They have tried the old rites recorded alongside the old warnings. They have tried isolating the eldest and most grey of the birds, the ones the team quietly considers the most overdue.

So far, nothing has worked. The birds sit warm and heavy and patient in their roosts. Professor Orrery would not put a number to the ticking clock and she was firm that no honest person could, because phoenixes were never studied in this condition. She would also say that while there is pent up energy in these phoenixes they still offer so much light and warmth to the city.

Perrin Callow writes for the Chronicle’s Science Desk. Professor Orrery’s rebirth study is housed at the University aviary at the edge of the square. Records of historical phoenix burnings, roost counts, or anything unusual observed at the towers may be sent to the desk by owl and will be held in confidence.