HDO(3_3,1–4_2,2) (upper), CH₃CHO(18_0,18–17_0,17) E&A (middle), and C¹⁷O(3–2) (lower) channel maps emitting v_sys ± 2–3 km s⁻¹ (blue and red) overlaid on top of the disc traced by Lee et al. (2017a) using ALMA Band 7 continuum observations (grey scale). C¹⁷O(3–2) emission (a tracer of the HH 212 disc at these velocities; see also Codella et al. 2014) has also been observed in our Cycle 4 dataset (Tabone et al. 2017). The first contours and steps correspond to 3σ (60 mJy beam⁻¹ km s⁻¹ for HDO and CH₃CHO, and 73 mJy beam⁻¹ km s⁻¹ for C¹⁷O) and 5σ, respectively.