BANFF, Alta. - "Dexter" creator James Manos Jr. says it was simply the right time to eliminate one of the show's most beloved characters in last season's shocking finale.

Anyone not caught up on the dark escapades of the fictional serial killer Dexter Morgan may want to stop reading here, lest they spoil one of the most devastating twists to come out of the provocative Showtime series, which aired on The Movie Network and Movie Central in Canada.

"It sucks, quite frankly, when anybody dies off the series," concedes Manos Jr., who wrote and cast the pilot but was not involved in Season 4.

"For the actual show itself, the big picture of the show, it was the right time, it was the right play. I think the writers who took over the show after I left did a really smart job. I thought they handled it really elegantly and I thought it seemed very natural and normal and the right thing to do."

Of course, "natural and normal" are relative concepts in the world of "Dexter."

Last season kicked off with the psychopathic blood-spatter analyst settling into fatherhood as he stalked a serial killer that seemed to do the impossible -- juggle a picture-perfect family life with a decades-long compulsion to kill.

But when Dexter finally does away with the so-called Trinity Killer, played by John Lithgow, he returns home to find he was too late to save one last victim -- his own wife, Rita. Sitting next to her in a pool of his mother's blood is their baby son Harry. In an instant, all the normalcy that Dexter believed was finally his comes crashing down in the most pointed way possible.

Dramatically speaking, killing off Rita was an inevitability, says Manos Jr., noting that from the very beginning, he envisioned her as the key factor that could make Dexter human.

"Her bringing that humanity into his life was great, it was the purpose of it, to see whether or not he's going to become human and stop," says Manos Jr., who adapted the pilot from the series of "Dexter" novels by Jeff Lindsay. He also won an Emmy for his work as a co-producer and writer on "The Sopranos."

"Is Dexter going to become so human that he stops killing? (But) we don't want him to stop killing because we want those bad guys to go."

Manos Jr. outlined the intricacies of building a TV show around serial killer at the Banff World Television Festival on Monday, and his afternoon session grew so popular that observers overflowed out of the hotel conference room in which it was held.

Other show creators and producers at the festival include the masterminds behind "Breaking Bad," "Glee," "The Big Bang Theory" and "The Good Wife."

Manos Jr. says he's happy to report that star Michael C. Hall is cancer-free. The actor had begun treatments for Hodgkin's lymphoma earlier this year but is now in complete remission, he says.

Shooting on season 5 is reportedly underway with rumours swirling that actress Julie Benz, who played Rita, will return in some form next year.

Manos Jr. says it takes guts for a show to kill a popular character, but that it also takes a strong story framework for a show to survive a twist like that.

"If you kill off one character and it kills the show it's not a well-crafted show," he says.

"(In writing) the pilot, you lay in a DNA. You lay in all these little bits in the pilot that ... will ultimately grow -- a little bit of a relationship between Laguerta and Dexter, a little bit of a relationship between Batista and Deb, certainly Deb and Dexter. You lay in all these tiny things that you go, 'OK, the DNA's been laid in, it can grow, it can have a life."

The Banff World Television Festival runs through Wednesday.