Bad characters, silly storylines.
Last month I missed two episodes in a row and didn't even bother to find out what happened.
But then, the Friday before last, Coro leaped back on to the rails and drove into the sunlight, carriages gleaming.
A toppermost episode, as Kirk would say, possibly one of the 10 best ever.
This was the classic hybrid of glorious high fun and pitch-black melodrama. If Coro episodes had names, it would be The Death Of Schmeichel.
My fondness, nay, adoration of the greatest of all Great Danes has been expressed here before.
Schmeichel was unquestionably Coro's finest character, and that he could actually die really makes this episode more Top Five than Top 10.
The mighty dog has, after all, albeit essentially without words, held Coro together for years, the glue that enables plot and characters both to move significantly forward, Schmeichel always watching, utterly compliant, sometimes even asleep, and usually in another building, while lying on the floor.
He nearly didn't die.
Chesney did everything in his power, squandering lent rent money on ludicrously futile veterinary bills.
Biopsies and operations happened willy-nilly in milly-seconds as Chesney kept shelling out the cash for Schmeichel, his eyes sunken, his chest heaving with liver cancer.
''I don't know the names of the body parts in Latin,'' says Kirk, Coro's second-best character and known for being less intelligent than nose hair, ''but I do know a dog who has had enough.''
''He doesn't look right,'' admits Chesney, the end now a sigh away from nigh.
But the writers were determined to make Chesney's idiocy match his dog love.
Chesney, abandoned by all his friends, skint, decides to carry Schmeichel, who weighs three tonnes - Chesney, it should be remembered, is a matchbox on two match-sticks - on to a bus to take him to a third vet.
Kirk at least understands Chesney's devotion, his love of a mere dog above that of his upcoming child, currently carried by his 16-year-old diminutive de facto.
''Some of my best friends have had four legs,'' Kirk says.
Chesney eventually calls the vet in to inject Schmeichel into dog heaven, which the vet does with Schmeichel fittingly on the floor, spread out like a huge heaving waterbed.
The dog dies, Chesney gives Camera One a face nobody with a heart will ever forget, we all cry, well, I did, and the dog ambulance drives off, Chesney's eyes burning into its bumper.
''This is one of the hardest things a man can do,'' Kirk says.
Kirk was on fire throughout this episode.
Hitherto starved of lines, possibly because in real life he has no memory, or possibly because he is a very well-drawn moron - philosophers have mused on this for years - Kirk makes it hard for the viewer by having only one facial expression, which he uses whether reacting to the merit of a meat pie or to the news his parents have just been eaten by a crocodile.
Impassive. Thick. Kirk in this episode redefined greatness in British television.
But there was so much more.
The wretched Brian hunkering down on the Red Rec with the once-wretched-but-now-cool Julie - wearing a red tea cosy, red being the mistress colour, always - to photograph UFOs, Julie straddled out beside him in the Y shape begging to be defoliated, with the unforgettable line - ''make love to me now and I'll promise to keep an eye out for little green men''.
Julie has waited so long, a pity the writers chose Brian to have the Powerball.
Or Tina, now forbidden to sizzle towel-covered in the flat, slagging a Sloane Ranger, ex-girlfriend of her wretched doctor, over dinner, go Tina.
And the wretched Chris gloating over the wretched Lloyd that he has been sleeping with the wretched Cheryl.
Lloyd weeps uncontrollably to the once-cool but now wretched Steve, and Steve replies with a line that only the greatest Coro episodes could come up with.
''Let's go bowling. The shoes are great.''
• Roy Colbert is a Dunedin writer.
