1967: TOS S01E27 ‘The Alternative Factor‘. Stardate 3087.6: Investigating the cause of a massive, galaxy-wide disruption in space, the Enterprise finds a mad scientist who claims he is being pursued by a hideous being. WATCH!
1992: TNG S05E19 ‘The First Duty‘. Stardate 45703.9: Following an accident during an Academy training exercise that leads to the death of one of his friends, Wesley Crusher must decide whether loyalty or truth is the first duty. WATCH!