Results of the default WSA–Enlil–SEPMOD simulation run (i.e., using the interplanetary shock source only) compared with observations of the 2021 October 9 CME and SEP event at five locations in the inner heliosphere – (a) Bepi, (b) SolO, (c) PSP, (d) STEREO-A, and (e) Earth. Each plot shows, from top to bottom: Magnetic field magnitude, solar wind bulk speed, proton density, proton temperature, and proton/ion fluxes. Magnetic field and plasma data are shown in solid black, while the corresponding simulated quantities are shown in solid magenta – the related ambient run (i.e., without CME) is shown in dashed magenta. Energetic particle data are shown with solid lines, while the corresponding simulated fluxes are shown with dashed lines. The (observed) arrival of the CME-driven shock is marked with a vertical grey line, where applicable. The heliocentric distances reported for each observer refer to the eruption time of the 2021 October 9 event.