On February 13th, 2023, the KM3NeT/ARCA telescope detected a neutrino candidate with
an estimated energy in the hundreds of PeVs. We review the observation of this ultra-high-
energy neutrino in light of observations above tens of PeV from the IceCube and Pierre Auger
observatories. Furthermore, we discuss how the ultra-high-energy data were fit together with
the IceCube measurements at lower energies, either with a single power law or with a broken
power law, allowing for the presence of a new component in the spectrum. Finally, we present the
prospects that may lead to resolving this apparent discrepancy and better characterise the neutrino
landscape at ultra-high energies.