The creators of television show Under The Dome - about a small town that finds itself suddenly trapped under an enormous invisible dome - could have limited themselves to the timeline of events set out in the Stephen King novel on which it is based.
But that would have meant running out of steam - and story - pretty quickly, especially as the goal was to produce a TV series that could air for many seasons.
As the science-fiction drama returns for its third season this month, the producers say they are trying to keep things fresh by introducing new people and fresh character development to the fictional town of Chester's Mill.
This includes a mysterious therapist character played by Marg Helgenberger of CSI fame, who joins a cast led by Breaking Bad's Dean Norris and tries to help the town's residents deal with being cut off from the world. The new season airs here on RTL CBS Entertainment HD (StarHub TV Channel 509, Singtel TV Channel 318) on Wednesday at 9.55 pm.
Speaking to reporters in Los Angeles, executive producer Neal Baer admits that the introduction of new characters is partly because the show is running out of disasters to throw at the town's residents.
"We have taken the viewers through all kinds of calamities, I don't know what's left. We had butterflies and caterpillars eating crops and acid rain and all kinds of things dealing with a parable of climate change.
"But now, it's really characteroriented and about how they're going to get out of this place with new calamities brought on by Marg's character," he tells Life and other media in Los Angeles.
Of course, this means explaining where the additional characters have come from, given that the dome is supposed to be impenetrable, even though it was revealed last season that it is possible for some people to leave.
The show will also continue to keep viewers guessing by revealing new facets of existing characters, especially the town villain, councilman Big Jim Rennie (Norris).
"I got nicer for a while," says Norris of his character's brief rehabilitation in Season 2. "But it didn't last," he adds, smiling.
"He's a complex character. Having lost his wife, that kind of does something to him. He goes through nice phases and tougher phases. But there's definitely a change in the character of Big Jim this year. And he gets a little friend who's a dog and you kind of see a little bit of his heart come out."
All of this is a considerable departure from King's acclaimed 1,000-odd page story, which takes place over the course of a week or so - a timeline the series had overshot by the end of the first season.
According to the producers, the show has the author's blessing in taking liberties with his 2009 book and, indeed, King even co-wrote an episode of the series and made a cameo appearance last season.
Mr Baer says: "We invited Stephen to write the first episode of Season 2 as a way to launch it for year two and to show fans of his work that he was very involved."
This year, the author will be less involved because he is busy with other film and TV projects, but Under The Dome still has his stamp of approval going into its third season.
"There's kind of a creepier factor in this season that really is us paying homage to Stephen," Mr Baer adds, noting that this will include details such as the name of Helgenberger's character, Christine - a reference to the possessed car in King's 1983 horror novel.
Whether these narrative strategies will work remains to be seen.
The first episode of Season 3 garnered good ratings in the United States earlier last week, where it was the top advertisementsupported scripted TV show among adults aged 18 to 49, even though its overall viewership has fallen sharply compared with a year ago.
Going beyond the scope of King's book has had mixed results critically, too, with Under The Dome's ratings plummeting on both the Rotten Tomatoes and Metacritic review aggregator sites between Seasons 1 and 2.
Despite an increasingly complicated plot, writer-producer Tim Schlattmann promises that fans will get answers to most of the questions raised so far, even as new mysteries are added to the mix.
"By the end of this season, you're going to know everything. There will be very few presents left under the Christmas tree that relate to everything you've seen, and a different perspective to the things you've seen before," he explains.
"That is certainly the case with this new character portrayed by Marg, who you're going to find out has been in Chester's Mill this whole time. So why haven't you seen this character? She has a cohort played by Kylie Bunbury, whose character's name is Eva, and these two people are new residents of Chester's Mill and yet they've been there the whole time. And that really is kind of the story engine for this entire season.
"It is going to feel much darker and much scarier this season - kind of in honour of the source material and the world that Stephen King created in the book."
•Under The Dome Season 3 airs on RTL CBS Entertainment HD (StarHub TV Channel 509, Singtel TV Channel 318) on Wednesday at 9.55pm.