Theoretical evolution path in the Hertzsprung-Russell diagram for stars in NGC 6752. Along individual tracks the solid line corresponds to the central helium-burning phase, and the dotted line to the more advanced phases (AGB or AGB-manqué). All models are computed with a value of η = 0.5 in the Reimers mass loss prescription, and we also show the prediction with η = 0.65 for the 0.79 M_⊙, Y = 0.263 model (long dashed). They correspond to a first-generation star (black) and to several second-generation stars (colours) that terminate helium burning at approximately 13.4 Gyr. The corresponding initial masses and helium abundances are given in the graph. The 0.82 M_⊙ star born with pristine helium as well as second-generation stars born with modest helium abundances evolve along the horizontal branch at a relatively low temperature and then all converge towards the AGB. Instead second-generation stars born with higher helium abundances evolve at much higher effective temperatures on the horizontal branch and become AGB-manqué.