Okay, we’ve got seven suspects for the murder of Brian McGonigle. All have a motive and the means to kill television’s most corrupt copper. But who actually dunnit? Would everyone assemble in the drawing room: Monsieur Poirot is about to reveal the murderer’s name.

A new season of Red Rock (TV3, Monday) kicks off this week, and viewers who have waited all summer to find out who killed Brian get their answer. But what makes this opening episode so gripping is the way the killer's identity is revealed. And it certainly isn't by a Belgian detective flamboyantly pointing a gloved finger.

TV3 has ramped things up for this new season, clearly out to make the most of the series’ huge success. (It’s been snapped up by both BBC and Amazon Prime and is up for a raft of Ifta awards next week.) It’s now been streamlined to one hour-long episode a week, and moved to a later, postwatershed time of 9.30pm, which leaves a lot of leeway for grittier, more violent and more mature storylines – not that it wasn’t all that gritty, violent and mature to begin with.

In fact I’m not sure if we can even call it a soap any more. Red Rock has grown into a full-badged police drama, and this season opener brings it further away from the Fair Cities and closer to the Love/Hates of this world.

The last series ended with a cliffhanger, as Det Insp Nikki Grogan looked up from her computer, having worked out who the murderer was, and the other gardaí waited expectantly. The pregnant pause lasted all summer, but when we return to the investigation room to pick up the story the teasing doesn't stop. We get lots of headshaking, incredulous staring at computer screens, lots of cries of "no way" and "we should have known". Even the killer's gender is coyly held back. "When are we going to bring them in?" asks Rory Walsh. It all seems a bit contrived. What next, a jet passing overhead just as someone says the killer's name?

What follows is an extended flashback that takes us through the final, frenetic hours of Brian's life – and makes the wait worth it. All seven suspects make an appearance, including wife Jules, spurned teenager Rachel, her junkie ex-boyfriend Conor, gangster Mick Moran and garda Sharon Cleere. We get thrown a few very obvious red herrings, and even after we witness the murder the teasing doesn't stop; we then wonder if the gardaí have got it right.

Whatever happens next, one thing is certain: we’re not in soapland any more, Toto.

There's a lot of nostalgia for how TV used to be, harking back to an idyllic time when the whole family sat around the gogglebox and watched the latest episode of The Bionic Woman or The Incredible Hulk. Netflix's Stranger Things tapped into our memories of creepy 1980s sci-fi, but now Sky1 is hoping to revive our interest in old-fashioned swashbuckling adventures in the vein of Indiana Jones and Romancing the Stone. And if that means reviving the old adventure-movie cliches, then so be it.

Hooten and the Lady (Sky1, Friday) follows the adventures of a posh archaeologist, Lady Alexandra Lindo-Parker (played by Ophelia Lovibond), who persuades her bosses at the British Museum to let her go to the Amazon jungle and search for the lost camp of the Victorian explorer Percy Fawcett. There she meets Hooten (played by Michael Landes), a rogueish American loner who survives by his wits (and a bit of thievery). They've both just been strung up by angry Yuruti tribespeople. (They actually exist.) At this stage your disbelief should be strung up and suspended over a big chasm with a crocodile-infested river below.

They escape rather too easily from the Yurutis, who for Amazon tribespeople don’t seem to be able to run very fast. Hooten tells her: “You know, you ask a lot of questions.” They disagree about the correct pronunciation of the letter Z. They find Fawcett’s lost camp. (They could hardly miss it, sitting atop its little hill.) They find a map that leads to the lost city of El Dorado. They fall down a gorge and land on top of each other, allowing for the requisite frisson of sexual tension. They find El Dorado more quickly than we could find the motor-tax office. They can’t stand each other, but of course we know they really like each other. And we get to quite like them, too.

Hooten and the Lady certainly fulfils its promise to be old-fashioned, wisecracking fun; despite its silly name it’s a pleasant change from the po-faced cop and superhero shows that clutter the Sky universe. But just because we like programmes influenced by old TV shows it doesn’t mean we want to go back to the way telly used to be.

Bands may come and go, but Later . . . with Jools Holland (BBC Two, Friday) just keeps on rocking. As the weekly music show heads towards its 50th series there's no sign of the Jools juggernaut stopping. That's because it's also practically the last TV music show standing. Okay, Ireland has Other Voices and The Imelda May Show (which borrows from the Later . . . format), but apart from the musical slots on Graham Norton and Jonathan Ross's chatshows, there's not much room on UK telly these days for bands to blast out their latest records. So the BBC is probably fulfilling its public-service remit by keeping the show going; otherwise it would probably have fallen off the stage and into extinction long ago.

The format has stayed pretty much the same: a bunch of bands and artists perform in the round while Holland plays ringmaster to this circus of sound. It’s usually a mix of hip new artists, marquee names, veterans out to prove they’ve still got their mojo, and unknown artists. At the end of each performance Holland sticks his head into the camera, like a sort of rock’n’roll telly selfie, just to remind you that he’s the man with the impeccable music taste curating the whole thing.

Series 49 opens with a heavyweight guest list. We have the US rockers Kings of Leon; the Geordie jazz-rocker Sting, who has gone back to his new-wave roots; and Jack White, who plays an old White Stripes song on acoustic blues guitar. There are no wow moments, but there are a couple of pleasant surprises: a song by the French band M83 starts off with smooth, jazzy sax but quickly blows up into a vibrant pop explosion.

As long as Holland keeps the mix of new bands and old treasures, there’s no reason why Later . . . can’t keep spinning around until the last CD sale is registered.