'How I Met Your Father' brings back a major character from the original series for the season 1 finale

• Warning: There are major spoilers ahead for season one of Hulu's "How I Met Your Father."
• The season one finale brought back a star from the core cast of "How I Met Your Mother."

Hulu's "How I Met Your Father," a continuation series following the events of CBS' hit sitcom "How I Met Your Mother," ended its first season with an appearance from a major cast member from the original show.

"HIMYF" showrunners Elizabeth Berger and Isaac Aptaker previously told Insider that the identity of the titular father wouldn't be revealed by the end of the 10-episode season, but fans could still expect a "satisfying" conclusion.

Tuesday's season one finale (titled 'Timing Is Everything") delivered on that promise by bringing back "HIMYM" actress Cobie Smulders, who starred as Robin Scherbatsky on the original show's nine-season run between 2005 and 2014.

True to the spirit of its predecessor, the finale showed the protagonist, Sophie, experiencing unexpected, major changes in her love life over the span of 1 episode

The episode picked up with Sophie (Hilary Duff) and Jesse (Chris Lowell) meeting up for a date after kissing for the first time in the penultimate episode.

Jesse revealed to Sophie that he met up with his ex, Meredith (Leighton Meester), to get some closure earlier in the day. Then, Sophie and Jesse ditched dinner to have sex.

While asleep in the middle of the night, Jesse told Sophie that he loved her. The moment was reminiscent of "HIMYM" character Ted Mosby (Josh Radnor) telling Robin that he loved her on their first date.

Sophie was freaked out by Jesse's semi-conscious declaration of love, but he told her that it wasn't too rushed considering that they've known each other for a while.

To make matters more worrisome for Sophie, Jesse revealed that he turned down the opportunity to play piano on Meredith's upcoming tour and get back together with her because he has feelings for Sophie.

In response, Sophie said that it was overwhelming to hear that he gave up his dream of touring to be with her. Angry, Jesse asked her to leave his apartment.

Sophie ran into Robin while trying to clear her head at MacLaren's, the iconic bar from 'HIMYM'

While ordering a drink from "HIMYM" bartender Carl (Joe Nieves), Sophie was interrupted by Robin, who was sitting alone.

Sophie immediately recognized Robin because after "HIMYM" ended, she became a famous reporter. In a nod to a moment from season seven of "HIMYM," Sophie told Robin that she was a big fan of a story she did in which she got in the ring with a bull.

Then the two sat at the original crew's booth and Sophie opened up about her love life woes, and why she felt like things with Jesse were moving too fast, too soon.

Robin helped Sophie realize that she was letting fear run her life and shouldn't waste time being scared. Sophie ran back to Jesse's apartment to make amends but when she reached the hallway, she saw Jesse and Meredith kissing in his doorway.

Sophie returned to the bar to tell Robin, who said that timing is everything when it comes to love and "sometimes, timing's a bitch." Before leaving, Robin told Sophie that she would be OK.

Heartbroken, Sophie met up with her friends, sans Jesse, at the opening night of her gallery show where a photo that she took of Jesse was on display.

The finale ended with another tie-in between 'HIMYM' and 'HIMYF'

The episode revisited The Captain (Kyle MacLachlan) and Becky (Laura Bell Bundy), two characters from the original show who made appearances during episode nine.

In the latest episode, the pair negotiated the terms of their divorce and Becky said that she was only interested in taking his "boats, boats, boats," a callback to a boat commercial Becky starred in during her time as Robin's co-anchor at "Come On, Get Up New York!"

To get revenge against her cheating husband, Becky told The Captain that she was going to sink his boats. The Captain told Becky that she could have all his boats, except for one that was in Australia.

"What those marine biologists are doing down there is important," he said. "They're trying to help coral reef procreate."

It was revealed that Ian (Daniel Augustin), Sophie's Tinder love interest from the season premiere, was on that boat owned by The Captain.

Becky didn't let Ian and the marine biologists continue their work in Australia, so Ian returned to NYC and showed up at the gallery.

The episode concluded with Ian asking Sophie, "Is this a good time?"

At the start of the series, it was revealed that the father is a character from the pilot.

The showrunners of "HIMYF" previously told Insider that the hope is for the show to have many seasons, which is why fans wouldn't get a definitive answer about the titular father by the end of season one.

But Ian's return to town puts him back in the running as the potential dad. Fans will have to wait until "HIMYF" returns for season two to learn what happens to Sophie, Ian, Jesse, and the rest of the characters.