NBC has not yet made a decision on the bubble show, which was saved from cancellation in 2017 after fan outcry.

[This story contains spoilers from Timeless' May 13 episodes, “The General" and "Chinatown."]

The fate of NBC's fan-favorite time-travel drama, Timeless, remains up in the air after its second season ended on a shocking cliff-hanger Sunday night.

"We're hopeful yet realistic," NBC boss Bob Greenblatt told reporters earlier that morning when asked about the series' fate. Timeless and the Mindy Kaling-produced freshman comedy Champions are the only undecided bubble series left at the network, and Greenblatt said a decision on their futures would come after the current seasons finish airing. "We tried to give the producers the courtesy of letting their shows run," he said.

The two-hour Timeless finale took the time-traveling team of Wyatt (Matt Lanter), Lucy (Abigail Spencer) and Rufus (Malcolm Barrett) — along with villain-turned-ally Flynn (Goran Visnjic) first to the Civil War, where they teamed up with Harriet Tubman to find a Confederate spy for Rittenhouse (the time-twisting organization attempting to change key moments in history), then to 1800s San Francisco Chinatown.

In the final moments of the first hour, Wyatt's wife, Jessica (Tonya Glanz), took pilot-in-training Jiya (Claudia Doumit) hostage in the Lifeboat time machine. The second hour took the team back to San Francisco's Chinatown in the 1800s, where Jiya was trapped, despite her warning them not to come.

It turns out that Jiya's vision of Rufus' future death, which she'd seen earlier in the season, actually took place there. After escaping the saloon where he was supposed to die, Rufus was shot and killed by Rittenhouse villain Emma (Annie Wersching) instead. Jiya, Wyatt, Lucy and Flynn returned to the present, where they were shocked by the appearance of a newer, more tricked-out Lifeboat — and the two people who stepped off of it: different versions of Wyatt and Lucy, who instructed the team to hop aboard to save Rufus.

Timeless was initially canceled after its first season in 2017, with NBC reversing its decision days later after substantial fan outcry online. And though the network has already earned audience goodwill this season by picking up comedy Brooklyn Nine-Nine the day after Fox canceled the Universal Television-produced show, low linear ratings do not necessarily bode well for Timeless.

Sony initially attempted to package Timeless alongside high-profile pilot L.A.'s Finest, Norman Lear's Guess Who Died and fellow bubble drama The Blacklist, but passed on both pilots and reached a separate deal to renew the James Spader drama.

Co-creator Eric Kripke tweeted a plea to fans Sunday after Greenblatt's comments came out, asking them to watch the episode live. "Listen, we can argue whether this is fair or just," he wrote. "But it's the reality of network TV. They listen to ratings. We HAVE to watch live TONIGHT AT 9. It's our best chance."