Sometimes, when Rex Grossman rears back and fires, it is the most frightening thing on Earth for this franchise. His decision-making literally has B-horror flick quality. You yell toward the celluloid figure before the throw, as if you are pleading for the teenager to get out of the house. But it’s too late. The ball is released.

It lives; it never dies.

Of course, that resilience is also the very part of the monster in Rex that keeps pulsating through the Redskins, why they keep ticking amid a very disappointing season even by Mike Shanahan’s transitional-year standards.

Grossman rears back again as he did Sunday at CenturyLink Field amid a howling mob and cold, damp, rotten Pacific Northwest weather. And he rears back again — undaunted by failure, unfazed by the man from the other team running the other way with the football, oblivious to the hate mail and sarcasm and the reality that the Redskins will draft a quarterback in the first round next year and he won’t be in Washington anymore.

And it happens. Three hundred fourteen yards, two touchdowns and a fourth-quarter comeback later, the creature who helped kill the season suddenly morphs into the hero who helped halt the longest losing streak of Shanahan’s career.

“I think earlier in the season, Rex did the same thing for us: He gave us hope,” said Santana Moss, one of eight receivers on the other end of 26 Grossman completions in Washington’s 23-17 victory. “As long as we go out there and run our routes the right way and get open, he’ll give us a chance to get the ball. His presence alone has kind of lifted a lot of guys’ spirits. Offensively, we had a rhythm with him earlier and just to have him back, that was one of our keys.”

Hint, hint: Moss isn’t the only one in the locker room who wonders why Grossman was pulled for John Beck — at a time the Redskins were technically still 3-1 but getting their clocks cleaned against Philadelphia.

In hindsight, if Mike and Kyle go back to early October, you wonder if they make that move knowing what they know now: that, counting preseason, Rex has now beaten out Beck twice for the starting job.

Anthony Armstrong, who made a surprise cameo when Grossman hit him perfectly down the left sideline with less than seven minutes left to play for the go-ahead touchdown, tried to play the politically correct game — before adding: “Look, you don’t like change. No one does. But you go with it because that’s what the coaches want. And when that doesn’t work, you make another change.”

“You want to know what it is about Rex?” Armstrong asked rhetorically. “It’s his confidence. His swagger. His experience in the offense helps too. But mostly, he’s not afraid to make the big-boy throw. He gets chastised for it in the media, but he will still throw it into double coverage because he thinks in his mind, ‘My guys can make a play for me.’ As a receiver, that’s the guy you want throwing to you.”

Double coverage? Hell, Rex will loft it into triple coverage. His deep route to Moss on Washington’s first possession of the third quarter portended the usual doom: an interception going the other way.

By the time the most wretched kicking game in the NFL had its league-high fourth field goal blocked and the Redskins trailed 17-7 with less than 10 minutes to go, all that was left for Grossman to do was be the terrifying Rex of this season, the T-Rex of his uneven NFL career.

But not Sunday, not after that 50-yard throw to Armstrong, not after Roy Helu scooted for a 28-yard touchdown.

“We have a great bunch of guys,” Grossman said after outdueling Seattle’s Tarvaris Jackson, a quarterback almost as maligned as he. “Our locker room has a lot of great character, a lot of team chemistry, a lot of good people. A lot of hard-working, tough, great football players that believe in one another.”

Belief. That’s the key right there. See, it doesn’t matter how many thousands of seasonticket holders and untold thousands more Redskins fans cannot fathom Grossman as a bona fide starter at the position for their team. His teammates do. That’s why they won Sunday on the road against an improving team that was coming off back-to-back wins, including dumping the Ravens here two weeks ago.

The Redskins don’t see the monster in Rex; they see a guy who takes a ton of punishment. They see a guy whose egregious errors are miscues of the heart — he actually believes that his receivers will make a play on a ball that probably shouldn’t be thrown.

“He’s a warrior,” Moss said. “He hangs in there and gets hit in the mouth but you know he’s going to get up and keep fighting.”

If this season has been about anything in Washington this season, it’s been about tolerance — accepting huge warts and flaws and trying to fathom that little, tiny light at the end of a long, dark tunnel.

It’s accepting Rex Grossman, everything the monster and the comeback QB is, at least until the draft.