Ah, the 1970s! The heyday of flared trousers, aviator shades and flowery shirts with monstrous collars stretching into next week. They were also a time of a monstrous serial killer who frequented the “hippie trail”, which connected Afghanistan and Thailand and points in between, especially Nepal. Much worse than just a slippery character noted for escaping from prison and otherwise evading justice, Vietnamese-born French con man, smuggler, jewel thief and habitual murderer Charles Sobhraj was responsible for the deaths of up to 24 backpackers and others who found their road to enlightenment permanently blocked. Tahar Rahim portrays the smooth sociopath in The Serpent (coming soon to Netflix), a chiller-thriller period drama evoking a relatively recent world of shocking naivety and trust that seems so alien today. It’s also a world brought convincingly back to life with the considerable help of Tim McInnerny as a Belgian diplomat-investigator and Jenna Coleman as Sobhraj’s conniving partner and aloof accomplice. Filmed mostly in Bangkok’s less modernised districts, with tantalising glimpses of a Hong Kong looking almost impossibly quaint and low-rise, The Serpent hisses with quiet menace from the start. Luring the unsuspecting into mortal danger and dodging police forces around Asia by using a collection of fake passports and identities, one of the 20th century’s most devious criminals built a revolving cult around himself – revisited here in all its apparently glamorous, but ultimately tacky, detail. Ten years later and half a world away, and we’re in a Los Angeles being terrorised by a repeat offender who favours more rudimentary methods. It’s 1985 and citizens are being shot, stabbed, strangled or bludgeoned in their homes, while children are being abducted and assaulted – all the crazed handiwork of one elusive man. “The monster was among us … hunting us,” recalls a reporter who covered the gruesome killings. “Anyone could be a victim.” He’s joined in Night Stalker: The Hunt for a Serial Killer , a harrowing Netflix documentary, by two lead detectives who obsessively stalked the Stalker, despite being repeatedly given the slip or stymied in their quest, not least by jurisdictional bungling and interdepartmental one-upmanship. Night Stalker can feel uncomfortably voyeuristic, with its liberal use of grisly police photographs showing the extreme violence with which families were ripped apart – a process that began with the murders of women of Chinese and Japanese heritage. This was the dark side of the American dream, a horror show in a sunny city that at the time was posting roughly 1,000 murders a year: times change, but not all that much. It turned out that the LA sadist was also a Satan freak – a type not unknown in Elizabethan England, if the witchfinders of the time are to be believed. Devilishly dark deeds are afoot in series two of A Discovery of Witches (Now TV channel 521; new episodes on Saturdays), a fantasy in which witch Dr Diana Bishop (Teresa Palmer) carries on searching for magical tome The Book of Life . Aided in her task by an extravagantly be-shirted Matthew Goode as her scientist-vampire lover, Matthew Clairmont, historian Bishop isn’t at all sure about this spell-casting lark. She wasn’t even certain she had supernatural powers until the splendidly named Goody Alsop (Sheila Hancock) convinced her to take up the wand. Being at the back end of the 16th century makes quoting King Lear marginally anachronistic, although such trifles are more easily airbrushed than the American accents. No matter: perhaps mind-muddling time travel, as required by a plot adapted from the All Souls Trilogy by novelist Deborah Harkness, can be used to justify anything. Unless … “that way madness lies”.