  We establish a hidden extension in the Adams spectral sequence converging to
the stable homotopy groups of spheres at the prime 2 in the 54-stem. This
extension is exceptional in that the only proof we know proceeds via
Pstragowski's category of synthetic spectra. This was the final unresolved
hidden 2-extension in the Adams spectral sequence through dimension 80. We hope
this provides a concise demonstration of the computational leverage provided by
$\mathbb{F}_2$-synthetic spectra.
