Not all spin-offs are created equal -- and while many spin-offs hit after the original series ends, some emerge during a successful show's run, like Young Sheldon bazinga-ing its way out of The Big Bang Theory. The former is already on its way to becoming a big hit, so shouldn't be facing cancellation any time soon -- but other spin-offs that ran concurrently with their parent show weren't so lucky.

The spin-offs below plucked their characters from the original and placed into a brand new environment -- only to then put them back in the first series like nothing just happened.

1. Ravenswood

Remember when Pretty Little Liars lost its mind for a hot sec and gave Caleb (Tyler Blackburn) his own show that was basically Supernatural meets The X-Files? While a show with that combo sounds amazing, it was anything but for this short-lived series. Caleb returned to PLL; but demons and spooky evil things didn't come with him.

2. The Blacklist: Redemption

The Blacklist's Tom Keen (Ryan Eggold) teamed up with private intelligence contractor Susan 'Scottie' Hargrave (Famke Janssen) in this super short-lived series. The spin-off only produced eight episodes before it got the ax, and Eggold waltzed back to The Blacklist for more shady covert operations.

3. Joanie Loves Chachi

Scott Baio, Erin Moran, <em>Joanie Loves Chachi</em>Scott Baio, Erin Moran, Joanie Loves Chachi

Happy Days lovebirds Chachi Arcola (Scott Baio) and Joanie Cunningham (Erin Moran) starred on their own show about pursuing music careers in Chicago. When it got the boot, the duo returned to Milwaukee, Wisconsin and joined up with the Happy Days gang, none the wiser.

4. The Lone Gunmen

The X-Files men John Fitzgerald Byers (Bruce Harwood), Melvin Frohike (Tom Braidwood), and Richard 'Ringo' Langly (Dean Haglund) got their own short-lived show investigating crimes and conspiracies. They eventually returned to the hit sci-fi show for both its final season and for the 2016 reboot.

5. Criminal Minds: Suspect Behavior

BAU's technical analyst Penelope Garcia (Kirsten Vangsness) helped out another profiling team on the first Criminal Minds spin-off. But when the show was canceled after airing 13 episodes, she went back to dedicating her entire time to her OG team like it was all just a dream. Pretty suspect behavior, if you ask us.

6. The Ropers

Norman Fell and Audra Lindley, <em>The Ropers</em>Norman Fell and Audra Lindley, The Ropers

Three's Company landlords Stanley Roper (Norman Fell) and Helen Roper (Audra Lindley) sold their apartment complex and relocated to another, dealing with new tenants while maintaining their eccentric personalities. A year after the show's cancelation, the duo returned to Three's Company for one final episode.

7. Checking In

The cast of the TV sitcom <em>The Jeffersons</em> (L-R Berlinda Tolbert, Sherman Hemsley, Isabel Sanford, Franklin Cover, Roxie Roker and Marla Gibbs (seated))The cast of the TV sitcom The Jeffersons (L-R Berlinda Tolbert, Sherman Hemsley, Isabel Sanford, Franklin Cover, Roxie Roker and Marla Gibbs (seated))

Marla Gibbs got her own spin-off of The Jeffersons, following the adventures of Florence Johnson after she accepts a job as a hotel maid. Unfortunately, the show wasn't "movin' on up," only lasting a whopping four episodes. Florence soon returned to her old job as George and Louise Jefferson's maid. Granted, The Jeffersons did try to explain her quick return by saying the hotel burned down, but that just made it even weirder and more off-putting.

8. The Girl from U.N.C.L.E.

David McCallum as Illya Kuryakin, Leo G. Carroll as Alexander Waverly, and Robert Vaughn as Napoleon Solo in the TV series <em>The Man from U.N.C.L.E.</em>, circa 1965.David McCallum as Illya Kuryakin, Leo G. Carroll as Alexander Waverly, and Robert Vaughn as Napoleon Solo in the TV series The Man from U.N.C.L.E., circa 1965.

This Man from U.N.C.L.E. spin-off was canceled after one season. Leo G. Carroll reprised his role as Alexander Waverly, playing several agents' superior. When the show got the heave-ho, he returned to the OG spy series.

9. Grady

Demond Wilson as Lamont Sanford, Whitman Mayo as Grady WilsonDemond Wilson as Lamont Sanford, Whitman Mayo as Grady Wilson

Sanford and Son's Grady Wilson (Whitman Mayo) starred on his own show for 10 episodes before NBC pulled the plug. Grady made his way back to Sanford and Son soon after, and that was that.

10. The Tortellis

Jean Kasem as Loretta Tortelli, Dan Hedaya as Nick Tortelli, Rhea Perlman as Carla Tortelli-LeBecJean Kasem as Loretta Tortelli, Dan Hedaya as Nick Tortelli, Rhea Perlman as Carla Tortelli-LeBec

Cheers characters Nick Tortelli (Dan Hedaya), Loretta Tortelli (Jean Kasem), Anthony Tortelli (Timothy Williams), and Annie Tortelli (Mandy Ingber) ventured off to do their own thing for 13 episodes. When the spin-off didn't pan out, they returned to hang out with the squad at the bar where everyone knows your name.

11. Baywatch Nights

David Hasselhoff, <em>Baywatch</em>David Hasselhoff, Baywatch

Baywatch's lifeguard Mitch Buchannon (David Hasselhoff) and police officer Garner Ellerbee (Gregory Alan Williams) joined forces to solve crimes and investigate sketchy situations. What that has to do with being a hot lifeguard is beyond me, but we were supposed to just act like it never happened.

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