Image Credit: Michael Desmond/ABCWhen ABC first launched FlashForward, the network and producers boasted of having a five-season story arc for the drama about life after an international black-out. Apparently, the plan laid out by David S. Goyer (The Dark Knight) and Brannon Braga (24) was so compelling, it ignited a network bidding war among the nets before ABC snatched the project. “These high-concept shows can be fantastic, but there are a lot of pitfalls,” ABC Entertainment President Stephen McPherson told EW back in September. “The fact that they had done their homework made all the difference.”

Did it? Tonight, ABC will air the drama’s 22nd and final episode of FlashForward, because the network decided against ordering a second season. After a respectable debut last fall — it averaged 12.5 million viewers — ratings plummeted throughout the season. (It didn’t help that the show, like V, went on hiatus over the winter.) Part one of the FlashForward finale on May 20 only averaged 5.3 million — down 28 percent from its season average (7.4 million), so it’s not likely that tonight’s Part 2 will do any better. Suddenly, all that talk about a five-year plan didn’t mean a thing if no one showed up to watch.

So will FlashForward go down as a cautionary tale about the pitfalls of planning ahead? For his part, McPherson doesn’t make any apologies about picking up a show with a deep mythology (after all, he did renew V for a second season). “In the end, FlashForward didn’t engage audiences like we hoped,” he told EW earlier this month. “A huge part of rebuilding the network is about taking chances. Some shows just don’t work out.”

Yet two of the industry’s preeminent drama producers — both of whom just wrapped heavily serialized shows — are suspicious of anyone who thinks they can dictate where a show can and should go. “I would be wary of five-year plans,” says Howard Gordon, the executive producer of 24, told EW. “There is certainly a benefit to knowing generally where you are going. But I also think there is energy to the unknown and to the improvisation of seeing where stories take you. Knowing where you are going is sometimes constricting because then you have to get there. You have to have a pretty big brain to think you know where a story is going to go.”

“Speaking from personal experience, the more terrified and assured of cancellation you are, the more likely you are to get through the next episode,” adds Damon Lindelof, the executive producer of Lost. “There’s a certain burden in the first year of a TV show that the audience and network put on you to explain what your plan many months (if not years) down the line is… but the more you think about what you’re going to write in six months, the less you’re thinking about writing the script that’s due tomorrow. The plan comes in time, but in that first season, the plan is completely moot if you don’t take the time to listen to what the show is telling you it wants to be.”

There is at least one more high-concept drama in the pipeline for the 2010-11 season that could come with its own deep mythology — Terra Nova, a drama about a family 100 years in the future that travels back to the prehistoric era. Ironically, Braga is an executive producer on that one too, along with Steven Spielberg, ex-Fox Chairman Peter Chernin, and agent-turned-producer Aaron Kaplan, among others. From what we hear, Braga — together with executive producers David Fury (24) and Matt Olmstead (Prison Break) — is working from a series bible left behind by Craig Silverstein, the drama’s co-creator (with Kelly Marcel) who is now running Nikita at the CW. But at least one source who’s talked to Braga says the writer is petrified about the colossal endeavor — so like Lindelof indicates, fear (not just pre-planning) can actually be good for the new show. Stay tuned.