JWST/NIRSpec spectrum of MARTA-4327. Top panel: Combined G140M/F100LP (green) and G235M/F170LP (red) spectrum. The main emission lines detected are reported. Middle panels: Zoom-in onto the region of the auroral lines, i.e., [O III]λ4363 and [S II]λ4069 in G140M (left), [S III]λ6312 and [O IIλλ7320,7330 in G235M (right). The PPXF best-fit to the spectrum is overlaid in red (continuum in green, emission lines highlighted in yellow), while the 2D spectra and the fit residuals are shown in the upper and lower inset panels, respectively. Bottom panels: Zoom-in onto the region of high-order Balmer lines (left), and Paschen and O I λ8446 lines (right).