Review: Endeavour (S4 E1/4), Sunday 8th January, ITV

Two days after the 30th anniversary of Inspector Morse’s first ever appearance on our screens, Endeavour keeps the torch burning with a fourth series. It’s been a patchy-old ride for Endeavour since its inception – yes, its air is thick with Morse lore and what people now call ‘easter eggs’, but over the course of…