Time-dependence of the He-burning luminosity (top panel), WD total mass (middle panel), and mass-transfer rate (lower panel, left y-scale) during the stage of He-rich-matter accretion. The two leftmost spikes in the upper panel show, for comparison, the He-burning luminosity during the last two (61th and 62nd) H-burning outbursts. The lower panel also presents the evolution of the abundances of ⁴He (solid cyan line), ¹²C (long dashed red line), and ¹⁶O (dashed blue line) as tracers of the chemical composition of the accreted matter (right y-scale).