In this Paper, heat slug propagation in the QUench Experiment on Long Length (QUELL) is studied with the 2-fluid MITHRANDIR model, which allows a finite coupling time between bundle and hole helium in a two-channel cable-in-conduit conductor. The same eight inductively heated and four resistively heated runs are considered in Part I. Good to very good agreement is shown between computed and experimental evolution of the conduit temperature T-jk at downstream sensors, as opposed to the poor accuracy of the 1-fluid simulations shown in Part I. The inlet mass flow is typically slightly overestimated, as with the 1-fluid model, resulting in a phase shift between computed and experimental T-jk. Some parametric effects are also analyzed. (C) 1999 Elsevier Science Ltd. All rights reserved.