THIS IS US -- "Jack Pearson's Son" Episode 115 -- Pictured: (l-r) Mandy Moore as Rebecca, Milo Ventimiglia as Jack -- (Photo by: Ron Batzdorff/NBC)"This Is Us" did not have the happiest of Valentine's Days. Instead, the show left fans with big potential clues on how beloved patriarch Jack Pearson (Milo Ventimiglia) will die.

We know Jack dies when The Big Three are teenagers. The Feb. 14 episode, "Jack Pearson's Son," ended Jack's storyline in that '90s timeline as he sat in a bar, eating a bacon cheeseburger alone, and -- big clue -- drinking away his sorrows. Jack and Rebecca (Mandy Moore) had just had a big fight about her secret past relationship with bandmate Ben (Sam Trammell) -- it only lasted two months, back when she was 19 -- and Jack's jealous (over)reaction, leading Jack to change his mind and say she shouldn't go on tour. They both said some things they probably regretted, with Rebecca getting in the last harsh shot -- saying she needed to have something for herself without Jack getting in the way. Before going off to have his cheeseburger (their planned meal together), Jack said he never thought of himself as being in her way.

It felt like foreshadowing, especially when the camera lingered on Jack taking another drink. He has a past with alcohol, and the scene left fans very worried about what's to come.

If Jack does die after driving drunk, it would certainly put a big dent in his Perfection armor. But he's still our Jack.

The only good news from the episode was for Miguel (Jon Huertas). While Jack worried about the chemistry between Rebecca and Ben during their Valentine's Day gig, Miguel only had eyes for a brunettte across the bar. And, in the modern storyline, Miguel and Kevin (Justin Hartley) had a sweet talk about how much Kevin can be like Jack. It breaks Miguel's heart that Kevin doesn't like him, since seeing Kevin makes Miguel feel like he has a piece of his best friend back. It was a good episode for Miguel, kinda taking some of the heat off of him for getting together with Rebecca at some point after Jack dies.

Eventually, Kate (Chrissy Metz) is going to tell Toby (Chris Sullivan) about how Jack died, so that may be how fans learn -- or we could see it play out during the '90s timeline. Maybe both in the same episode? Season 1 has 18 episodes, and Episode 15 just aired, so we only have a few weeks left to learn The Truth About Jack. No matter what happened, it is going to hurt to find out.

"This Is Us" airs Tuesday at 9 p.m. on NBC.

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