Gamma-ray spectra at 10 and 1000 days given very neutron-rich ejecta from an NSM located at 10 kpc. Gray lines show the total prompt gamma-ray signal emitted, while black lines show the total signal after our radiation transfer calculation. Green lines show the contribution from β-decays to the observable gamma-ray signal, while the purple lines show the contribution from fission. The gray shaded band shows the sensitivity limit range for the AMEGO detector.