It's been a whole day since the interwebs were set abuzz by the shocking ending of last night's episode of 'How I Met Your Mother.' The episode had a lot going on, from the discovery of the gang's last doppelganger to a montage of Robin's embarrasing on-camera moments.

But the most talked about aspect of the episode, aside from the shocking ending, was the cleverly-presented countdown from 50 to 1, telegraphing the 'Bad News' of the episode's title. Many people got caught up in finding the numbers and figuring out what they meant. But as far as executive producer Carter Bays was concerned, he would have been content if people hadn't noticed them so quickly.

"I was surprised that people caught it, actually," he told me earlier this evening. "I thought it would be a thing you notice three viewings in, but I guess it was a little more visible than we intended."

What people found out about the countdown was that it wasn't counting down towards a happy event, like Lily (Alyson Hannigan) being pregnant after months of trying. It ended up counting down to a tragic event, the death of Marshall's (Jason Segel) father, played by Bill Fagerbakke.

It was a tough ending for fans of the show to take, but Bays and his producing partner Craig Thomas felt that it was an issue they had to explore. "As difficult as it is to say, that is real life. These kind of moments happen when you don't expect them. We wanted to shock the audience the way the characters were shocked. So much of what we love about the show is the relatability of it, and we try to create characters and stories that people see themselves in. As we've ticked off every milepost of young adulthood, sadly this is another one of those mileposts."

So they used the countdown, a conceit Bays admitted was cribbed from the 1988 movie 'Drowning By Numbers,' to give viewers a sense that something was coming. "It's hard navigating the amount of a sucker punch you want it to be," he said. "We wanted to have a little bit of foreboding in the air, and a little bit of raised eyebrows and suspicion that maybe something bad was going to happen. That's why we called the episode 'Bad News.'" A line Lily utters in the early going about "a black cat running through my uterus" also foretold what might happen.

"You talk about a difficult assignment... It's hard to add a sense of foreboding to a sitcom," Bays said. "But we wanted to add a sense that something was amiss, and this kind of felt like the way to do it." Bays credited episode writer Jenni Hendricks and the props, senic and post-production departments for making the countdown possible, even if it was more obvious than he expected.

That countdown got a mixed reaction from fans and critics; if you noticed it the first time you saw the episode, it made the shocking ending more dramatic, but if you didn't notice it, going back to look for the numbers felt like a distraction. Even the folks here at TV Squad were split on the device; Mo Ryan hated it, while I bought into that sense of foreboding Bays talked about.

'Bad News' had many callbacks to previous episodes, from the re-appearance of Alexis Denisof as Robin's (Cobie Smulders) old co-anchor Sandy Rivers, Barney (Neil Patrick Harris) in the Sensory Deprivator 5000, and the appearance of Barney's doppelganger, who just happened to be a fertility specialist. While it's fun to call back characters from five seasons ago and props that people haven't seen in a few years, Bays and Thomas still try their best to make the show accessible to people who haven't been ardent fans since day one.

"Our yardstick is always, if yo've never seen an episode of the show, you know what's going on," Bays said, adding that "We never want to be so up our own asses that you don't get the joke or it's not funny at all unless you've seen the other episodes."

So what does the death of Marshall's father mean going forward. Firstly, it won't mean that Marshall won't become the downtrodden middle-aged man we've seen him as in earlier episodes. That was more of a function of how Segel played him, according to Bays.

"I think the first time we did it, I remember thinking that he acted so old, I was like, 'How old are these guys, really? They're like 50 but he acted like an 80 year old.' But, yeah, this season is a big journey for Marshall, certainly, and stuff we've established early on.

"I wouldn't say Marshall is beaten down by the world in any way," Bays continued. "He's still Marshall-like, he's just older a little bit and a little bit more distinguished. But, this certainly will change a lot of things for them; it's as big a deal as you might imagine it would be for Marshall in the coming episodes."

What will we see in the second half of the season? More Jennifer Morrison as Ted's (Josh Radnor) frenemy Zoey, if Bays gets his wish. He'd also love to work with Kyle MacLachlan -- "He's just been one of the finest actors we've ever had on our stage," said Bays -- and Bob Odenkirk again.

But, mostly, the tragic event in Marshall and Lilly's life is going to be what reverberates from here on out. "I feel like the first half of the season was us getting all our ducks in a row, and the second half, from this event that just took place, the reamining 11 episodes will be how things unravel as a result of this little particular spark. Barney's search for his dad, Ted's relationship with Zoey -- or Ted's friendship with Zoey -- Robin's new career, all of these things will be affected by what just happened."



'How I Met Your Mother' airs Mondays at 8PM ET on CBS.

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