As part of The Big Bang Theory's historic final season, CBS has announced plans to crossover the series with its spinoff Young Sheldon. While co-creator Chuck Lorre already boasted a winning track record prior to its debut, one imagines most involved with The Big Bang Theory didn't anticipate that it would continue on for well past a decade. After all, new TV comedies debut every year, and the vast majority are lucky to even survive their first season, much less get a second one. The current TV landscape is one where if a show doesn't catch on quick, it'll find itself in the cancellation bin, especially on one of the big broadcast networks.
Thankfully, The Big Bang Theory was a sizable hit from the start, despite its debut season being shortened to 17 episodes due to the 2008 Hollywood writers' strike. The highest rated comedy on broadcast TV for the majority of its run, Big Bang Theory hit its peak in that regard during season 9, averaging a 5.8 in the 18-49 viewer demographic and over 20 million viewers per episode. Even now though, the show is a ratings smash, explaining why CBS initially wanted to sign the cast to new two-season contracts earlier this year.
That didn't happen though, reportedly thanks to star Jim Parsons - the Emmy-winning actor behind fan-favorite character Sheldon Cooper - not wanting to return. There's no show without the main Sheldon-Leonard-Penny dynamic that's been there since the beginning, so CBS opted to make season 12 the show's final outing. Season 12 has been met with much fanfare, and will see the return of several beloved guest stars. Now, EW also reports that cast members from successful single-camera spinoff Young Sheldon will appear on Big Bang Theory before the end, in a huge crossover event.
The Young Sheldon cast members set to appear on The Big Bang Theory are titular star Iain Armitage, Lance Barber (Sheldon's father George), and Montana Jordan (Sheldon's older brother Georgie). Those wondering how exactly those actors can reprise their roles aren't wrong to do so, as Young Sheldon of course takes place decades before Big Bang Theory, and Sheldon's dad has been canonically dead since 1994.
It's always possible their appearance could happen in a flashback scene, but it wouldn't be much of a crossover if they didn't get to interact somehow with Big Bang's cast. Perhaps some type of dream sequence involving Sheldon could resolve the timeline issue. Fans will just have to wait and see how The Big Bang Theory ends up making a Young Sheldon cameo make sense in context, as for now, neither CBS or producer Warner Bros. TV is offering any clues as to how it'll be pulled off.
The Big Bang Theory season 12 and Young Sheldon season 2 air Thursdays on CBS.