Channel maps of V1425 Aql for the lines of Hα (top row), [NII] λ 6584 Å (middle row), and [OIII] λ 5007 Å (bottom row). Each channel map shows a region of 15 × 15 arcsec². In all cases, the fluxes are presented in linear scales, with their ranges defined in the colour bars and the position of the binary marked with a white cross. For each line, the velocities were chosen to illustrate the behaviour of the different lines. The behaviour of the strongest lines in the nova shell as a function of their velocity illustrates the structures hidden within the inner shell, previously unnoticed in T23.