Inspiral of a 0.2 M_⊙ companion through the envelope of a 2 M_⊙ red giant, using four drag force prescriptions: our fitted drag and lift prescriptions (Eqs. 36–36b; solid blue); the prescription from De et al. (2020, orange); the Hoyle–Lyttleton formula, F_drag = πR_a²ρ_∞u_∞² (green); and our fitted drag prescription but with F_⊥ set to zero (dashed blue). For clarity, trajectories are shown only for r ≥ 0.25. Below this radius, trajectories start intersecting with themselves, corresponding to interaction with the companion’s own wake, which is not included in our model. At such small orbital separations, interactions with the primary’s wake would also play a major role in the orbital evolution.