  We present new JWST/NIRSpec IFU observations of the J1000+0234 system at
$z=4.54$, the dense core of a galaxy protocluster hosting a massive, dusty star
forming galaxy (DSFG) with a low luminosity radio counterpart. The new data
reveals two extended, high equivalent width (EW$_0 > 1000$ {\AA}) nebulae at
each side of the DSFG disk along its minor axis (namely O3-N and O3-S). On one
hand, O3-N's spectrum shows a prominent FWHM $\sim1300$ km s$^{-1}$ broad and
blueshifted component, suggesting an outflow origin. On the other hand, O3-S
stretches over parsec and has a velocity gradient that spans $800$ km s$^{-1}$
but no evidence of a broad component. Both sources, however, seem to be powered
at least partially by an active galactic nucleus (AGN), so we classify them as
extended emission-line regions (EELRs). The strongest evidence comes from the
detection of the high-ionization [Ne V] $\lambda3427$ line toward O3-N, which
paired with the non-detection of hard X-rays implies an obscuring column
density above the Compton-thick regime. In O3-S, the [Ne V] line is not
detected, but we measure a He II well above the expectation for star formation.
We interpret this as O3-S being externally irradiated by the AGN, akin to the
famous Hanny's Voorwerp object in the local Universe. In addition, more
classical line ratio diagnostics (e.g. [O III]/H$\beta$ vs [N II]/H$\alpha$)
put the DSFG itself in the AGN region of the diagrams, and hence the most
probable host of the AGN. These results showcase the ability of JWST of
unveiling highly obscured AGN at high redshifts.
