How I Met Your Mother Season 8 will show why Robin has called for the Best Man at her wedding - a cliffhanger at last season's sneak peek into the future. Cobie Smulders, who plays Robin, says even she does not know how her wedding arc will develop.

'Mysterious' show

"Our show is very mysterious and we like to keep it that way - even for people who work on it!" Smulders told Access Hollywood.

Will this wedding progress despite the bride's and groom's jitters?

"I don't really know. I think that they're intending to get married. I don't know what's going to happen," she said.

Smulders may not be speaking much because she has not read the scripts leading to the wedding, but co-creator Craig Thomas knows more.

In a separate interview with TV Guide, Thomas spilled that as far as the series is concerned, Barney (Neil Patrick Harris) and Robin are destined to be together.

"We always knew it was gonna be Barney and Robin," he said, adding that Barney's engagement to Quinn (Becki Newton) is only "about misdirection and magic."

How I Met Your Mother Season 8: A list of spoilers

Several spoilers have been released on what will happen next to the gang. Here are some of the best spills:

- There will be no time jump in the Season 8 premiere. The show is picking up where it left off. Fans can expect a brief but legendary continuation of the future wedding. Then the show will go back to the other cliffhanger: What happens next to Ted (Josh Radnor) and Victoria (Ashley Williams)?

- Robin will date her old crush, a character introduced briefly last season. "Battlestar Galactica" actor Michael Trucco will reprise his role as "Crush," but this time, his name will be revealed.

- Lily (Alyson Hannigan) and Marshall (Jason Segel) will dive deeper into parenthood. Eventually, they will be seeking Robin's help to babysit their bundle of joy, Marvin Waitforit Eriksen.

- At least three break ups and endings will unfold next season: Barney and Quinn, Robin and her crush, Ted and Victoria.

How I Met Your Mother will return for its eighth season on September 24. Negotiations are still ongoing for Season 9.