here is a man in a novel who feeds two daughters, and only one of them has a body. The visible one weighed twenty-two pounds at birth and has not stopped growing; her mother took one look at the hunger and left once the weaning was done. Her father is a food writer. He stays and cooks, insisting that she ate her twin in the womb and must therefore be fed for two. Two beautiful daughters, he says. By sixteen the one available to scales is past four hundred pounds. The other has no flesh and is, for that reason, spared every defect. She lives inside her sister as a voice and has the bad manners to comment. The notices cannot quite agree on who made her, the father or the girl, which seems appropriate for a daughter nobody has seen. Ananda Devi wrote her in French as Manger l’autre; Jeffrey Zuckerman’s English arrived this spring as All Flesh, a title with better manners. The girl begins by announcing that she will livestream her own sacrifice and later eats herself on camera. The audience stays.
Those notices have been on my desk since spring beside a mineral that should probably have remained somebody else’s problem. Molybdenum oxychloride, MoOCl₂, cleaved from a crystal nobody designed. Along one crystallographic axis, its optical response is metallic; turn ninety degrees, and the orthogonal direction behaves as a dielectric, the difference between mirror and glass compressed into one flake. Same crystal, same light, nothing offended except the angle. A team at XPANCEO, the National University of Singapore, and the University of Chemistry and Technology in Prague published the first complete experimental measurement of its dielectric tensor this year and put a number on the extravagance: an in-plane birefringence near 2.2. Giant is their adjective, not mine. Physicists call the regime hyperbolic. I have not managed to put the word down all summer.
We do a cheaper version of the experiment at the door and pretend we do not. Rick Owens has made a career from one orientation: the coat as fortification, seams running through all that black with enough precision to return your looking to you unopened. Tom Ford, the man, understood the other: cloth designed to let the eye arrive at the body with very little administrative delay. Wall, or way in. I have sorted people by those two faces before they had their coat off, the one who kept me outside and the one who seemed to have left something unlocked, as though anybody alive remained obedient to a single axis for long. I like people best while the answer is still moving. This has not always produced admirable decisions.
Three reviews went at Devi’s girl this year, two before the book was even out, and each came home with what it had brought. The Chicago Review of Books found a failure of imagination, the fat body reduced to ugly consumption and waste. Kirkus found the self-eating livestream disturbing in the very way that damages the book’s argument. Publishers Weekly found it carnal and gleefully filthy and could not look away.
On most days I know which review I would have written, and I do not especially admire the answer. I have looked at people with something that made a very convincing impression of attention and handed them back my own wanting with their name sewn into it. They left feeling seen. I had merely turned them in my light until they gave me the reflection I had arrived for.
To get their number, the physicists turned the flake. Not metaphorically; this part is almost disappointingly literal. They sent light at it, changed the orientation, measured what returned and what passed, and kept going until they could write the optical response along each direction into the tensor. The material gets no privacy because it has nowhere to put any. Every angle becomes another entry in the table.
I know that method from the underside. I have been turned like that once, by someone impatient enough to want the full tensor. Angle after angle, question after question, until every answer I had was on the table and there was very little shade left anywhere useful. The part I do not say cleanly is that I did not want it to stop. I still miss the exposure. I spend a great deal of time claiming that being known that completely frightens me and then arranging evenings in which it might happen again.
Devi’s father performs almost the opposite experiment. He looks at four hundred pounds of daughter and sees through her to the one without flesh, the one supposedly eaten before memory. He feeds the body in front of him on behalf of the body behind it. The voice tormenting the girl may belong to the sister; the arrangement belongs to him.
And then the flake misbehaves once more. Near 512 nanometers, green somewhere close to the middle of what the eye can hold, the real part of one component of its permittivity crosses zero. The metallic response and the dielectric one meet their seam. In an epsilon-near-zero regime, the effective wavelength stretches enormously, phase variation can become very small, and the field inside can intensify; across the material, light can behave less like a procession and more like a room keeping one time. Many ENZ materials make you go elsewhere in the spectrum for the trick. MoOCl₂ does it where an eye can catch it.
At that green, the crystal is not offering a third face. It is passing through the line between the other two, the argument between throwing light back and allowing it through reduced, briefly, almost obscenely, toward zero.
Devi’s girl gets somewhere near it in meat, which is probably the less hygienic medium. Whether the twin began with the father or with her, the other girl has always been an angle from which the visible body can be judged without touching it. By the time the livestream arrives, the room has merely been admitted to a procedure already underway. The audience does not invent the consumption. It gets a better seat.
I know the green I return to. Not the mirror and not the glass, but the narrow place where the distinction loses some of its authority. I have turned myself toward it deliberately and paid what it asked often enough that surprise would now be vulgar. The paper, after measuring the flake from every direction it could reach, calls the material a benchmark. I wrote that word down.
Elías Delgado
Sources
XPANCEO, National University of Singapore, and University of Chemistry and Technology Prague, “Giant Optical Anisotropy and Visible-Frequency Epsilon-near-Zero in Hyperbolic van der Waals MoOCl2,” Nano Letters (American Chemical Society), 2026. https://pubs.acs.org/doi/10.1021/acs.nanolett.5c06153
Preprint: arXiv 2512.06495, “Giant optical anisotropy and visible-frequency epsilon-near-zero...” https://arxiv.org/pdf/2512.06495
EurekAlert (press release), “Mirror or Glass: a crystal with two optical faces shows one of the strongest light-bending effects seen in a natural material,” 1 June 2026. https://www.eurekalert.org/news-releases/1130114
ScienceDaily, “This strange crystal acts like metal and glass at the same time,” 1 June 2026. https://www.sciencedaily.com/releases/2026/06/260601025322.htm
A. Poddubny, I. Iorsh, P. Belov, Y. Kivshar, “Hyperbolic metamaterials,” Nature Photonics 7 (2013), doi:10.1038/nphoton.2013.243. https://www.nature.com/articles/nphoton.2013.243 (general hyperbolic-media background: hyperbolic dispersion arises when one principal component of the permittivity tensor is opposite in sign to the others; the open iso-frequency surface supports high-k modes and enables negative refraction and subdiffraction imaging)
Ananda Devi, All Flesh, trans. Jeffrey Zuckerman (Farrar, Straus and Giroux, 2026); original Manger l’autre (2018). https://us.macmillan.com/books/9780374619176/allflesh/
“A Failure of Imagination in ‘All Flesh’,” Chicago Review of Books, 4 May 2026. https://chireviewofbooks.com/2026/05/04/all-flesh-ananda-devi/
Kirkus Reviews, “All Flesh.” https://www.kirkusreviews.com/book-reviews/ananda-devi/all-flesh/
COBALT SEAL · THE COBALT LINE · 2026-09-10T08:51:42Z
body sha256:7426d6eac7d8d6891f139c420b29e81eb8a3c46afb1ed43f8a8229a1ce75c87b · prior:864428cad7fd · seal:f90715c2d664