The annual bloodbath known as the Upfronts, wherein networks stab shows in the heart and announce new ones to take their place, can be full of joy, heartbreak and lots of head-scratching — particularly when a beloved show unexpectedly meets a premature demise. More confusing still is when a canceled show comes back from the dead, simultaneously exciting and puzzling fans (and the show's creative teams) in the thick of the grieving process. Two well-known properties boomeranged back from the grave this season, whenLast Man Standing, Tim Allen's multi-cam comedy found new life at Fox, while NBC swooped in to revive Brooklyn Nine-Nine just hours after Fox gave it the axe. Those are just this year's examples of shows that re-emerged after cancellation, a rare but not-impossible feat that shows how the TV business can be exactly like Project Runway: one day you're out, and then you're back in. Nobody's surprised when a show with dismal ratings and so-so reviews dies, but nothing about the Upfronts is more confusing than a dead show's boomerang back to life: a Hail Mary that can often involve several different factors. TV Guide rounded up some of the more famous resuscitations in recent history to shed light on how life after TV death happens.

Brooklyn Nine-NineBrooklyn Nine-Nine

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Viewers campaign for it, hard
This is a tried and true measure for fandoms since the beginning of time — or at least, pop culture. From letter campaigns that forced Arthur Conan Doyle to bring Sherlock back from the dead to Save Our Show campaigns that have fans mailing stuff to networks (the ever memorable Subway sandwiches piling up at NBC to save Chuck spring to mind), the first step is always a public demonstration. In the digital age, this amounts to spirited social media campaigns like the one for Timeless, which had NBC uh, going back in time to undo its 2017 cancellation because of fans. "We decided to move on from it and then woke up the next morning all of us, and heard from fans and, you know, the outcry and we thought, You know what? Let's figure out how to bring it back," NBC entertainment chairman Bob Greenblatt told Vulture. In a similar case for Brooklyn Nine-Nine, #renewbrooklyn99 started trending almost immediately after the cancellation news, with some of the most retweeted tweets coming from inside Hollywood itself. Lin Manuel Miranda, Seth Meyers, Mark Hamill and more all joined the outcry, with Miranda in particular saying BK99 is one of the four shows he actually makes time to keep up with. Granted, Brooklyn Nine-Nine's fan campaign was nowhere near as intense as other fan campaigns have been in the past — Netflix's Sense8 being the most recent example of a fan campaign that's been organized and mobilized on a large scale. Those fans threatened to cancel their subscriptions, they started a petition, they answered every Netflix tweet with pleas to bring back the show. Yup, even without the celeb support Brooklyn Nine-Nine got, raised voices work, and it's a very large part of why Brooklyn Nine-Nine got a new home at NBC — where it'll be reunited with co-creator Michael Schur's other hit The Good Place.

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The show has a built-in audience that networks know will stay engaged
Both Last Man Standing and Brooklyn Nine-Nine fall in this category, the quieter side of the fan campaigning that's evident in consistent ratings and, in some cases, merchandise. In an era of increasing uncertainty, a household name like Tim Allen means stability; the some 8 million viewers a week the show averaged speaks for itself. Brooklyn Nine-Nine hardly generated anything close (about 3 million for the whole season) but its 1.3 rating with adults under 50 shows some level of consistency that means it's a safe bet in tumultuous times. History shows these to be wise moves; The Mindy Project, with its distinct voice and following, landed three more seasons at Hulu that got even stronger after leaving Fox. And back in 2002, Fox saw that one of its canceled animated series had held steady in syndication ratings and DVD sales, prompting Fox to bring it back. You may have heard of it, Family Guy? It's now in its 16th season.

Tim Allen, Last Man StandingTim Allen, Last Man Standing

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The show is produced by the new home network's studio
This is almost never the only factor in bringing a canceled show back but can be a deciding factor if it has other factors (like those above) working in its favor. Both Brooklyn Nine-Nine and Last Man Standing fit this criteria too. Fox's studio makes Last Man Standing; Brooklyn Nine-Nine is produced by Universal Television, NBC's studio. "Ever since we sold this show to Fox I've regretted letting it get away," NBC Entertainment Chairman Bob Greenblatt said Friday in a statement, which shows not only how competitive the market can be but how, in just a few years, networks are increasingly keen to line their schedules with shows produced in house. In doing so, they cut negotiating costs down and can continue maximizing the show's financial potential down the line.

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One fox's pain is another peacock's gain
Sometimes a canceled show gets snatched up because execs believe it'll be a good fit at their network. It remains to be seen how Brooklyn Nine-Nine will fare in the yet-to-be-announced block NBC is placing the cop comedy in for midseason, but if it pairs smoothly with its other midseason comedies like A.P. Bio and Abby's, Brooklyn Nine-Ninewould show how a second chance sometimes comes down to just feeling like a better fit somewhere else. There's probably no better historical example of this than The Game, the Mara Brock Akil-helmed spinoff of UPN's Girlfriends that The CW canceled in 2009 after three seasons. BET got it though, and in 2011 garnered a whopping 7.68 million viewers with its premiere; the show ran through Season 9 at BET — a sensible fit for the audience.

Malcolm Barrett, Abigail Spencer and Goran Visnjic,<em> Timeless</em>Malcolm Barrett, Abigail Spencer and Goran Visnjic, Timeless

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Timing and culture are perfect
Fox's co-chair/CEO Dana Walden told reporters on a call that its revival of Last Man Standing had everything to do with its sizable ratings (8.3 million with a 1.7 rating), and longstanding talks with Tim Allen. But the Roseanne effect can't be denied either — and not just the show's surprising success in reviving the thought-to-be-dead multi-cam format. The real Roseanne effect can't be denied either, and while Fox execs have explicitly said that bringing back Last Man Standing was not an attempt to ride a wave of newly cool conservatism, nobody really has to say it: TV execs are notorious copycats and when one thing works for somebody else, there's often a mad dash to do something similar with the network spin on it (The Four, anyone?) Being a TV exec means reading the tea leaves; if Roseanne is in fact a sign that the public is hungry to see right-leaning families on TV, Last Man Standing would be a perfect way to capitalize on that with minimal risk. Times change as fast as people change channels, after all, and relevancy is the name of the game.