Observations are drawing a complex picture of the latest stages of massive stars evolution and their explosions. In this seminar I concentrate on two among the least understood aspects, adopting an observational perspective: (i) How do massive stars loose a significant fraction of their mass in the years preceding the explosion? (ii) What is the role of central-engines in explosions originating from progenitors that managed to loose their entire hydrogen envelope? I address these questions taking advantage from panchromatic observations of two remarkable explosions: the puzzling, double explosion of SN2009ip in 2012, and the mildly relativistic, engine-driven SN2010bh, that bridges the gap between ordinary explosions and fully relativistic gamma-ray bursts.