Scematic diagram of the inner wind of π¹Gru. In the center is a cut-out of the 120σ_rms contour of the ALMA continuum, from which the inclined spiral is launched. The colours of the spiral represent the different diagnostics used: blue is the SiO, green is the HCN, grey is the CO emission, and black is the stream of accelerating gas probed by the maser emission. The dashes parts represent regions of overlap.