'Big Bang Theory' Collides With 'Young Sheldon' in Special Crossover Episode

The Big Bang Theory crossed over with Young Sheldon Thursday night in an attempt to help Sheldon [...]

The Big Bang Theory crossed over with Young Sheldon Thursday night in an attempt to help Sheldon Cooper with an identity crisis.

The beloved CBS sitcom found Sheldon (Jim Parsons) reeling after Leonard (Johnny Galecki) revealed that his and Amy's (Mayim Bialik) theory had been debunked by Russian scientists, making months of work completely worthless.

Unaware of how to make their friend feel better after the disappoint news, Leonard remembers an old video tape Sheldon gave him in the past containing an old pep talk from his younger self left unwatched and only to be used in an emergency.

Amy sits Sheldon down and they both watch the sweet video from Young Sheldon himself (Iain Armitage).

"I was saving it for the day they stopped making Star Wars movies," Sheldon admits to his wife. "I don't think that's ever going to happen."

"How long has it been since you've seen it?" Amy asks.

"Not since the day I recorded it. I had just watched Back to the Future 2, where Marty McFly gets a glimpse of his future self and that got me thinking... the day may come when I needed my help," Sheldon says.

Amy starts the video and spots the younger Sheldon, commenting on how cute he is in the tape.

"Amy, please. Of course I was cute, look how I turned out," Sheldon says.

"If you're watching this, I assume something bad just happened," Young Sheldon begins.

"Something unfortunate and unforeseen. Something that's making you question everything..." he adds.

"I'm so smart," the older Sheldon interjects.

"Now, just to make sure it's really you watching and not an imposter. What am I thinking of," Young Sheldon begins to count down and then unison they both scream "Robot Monkey Butler."

"Should I leave you two alone?" Amy jokes.

"Sheldon, never forget. No matter how bad things seem, you can al-" he says before the video is interrupted by a recording of an old football game.

Older Sheldon begins to panic, angry that his father recorded it over his warning.

Fans of the CBS series were delighted to see the Sheldons collide in the scene.

"Young Sheldon appearance in #BigBangTheory = awesomeness. Robot monkey butler," one user wrote.

"Well, that was a quick [crossover]. Now Sheldon is even more broken than before, damn it football!" another user commented.

At a loss for what to do next, the group continues to try and help Sheldon move past his paper and Amy and him sit down to finish watching the video.

The recording shows Sheldon's dad George Sr. (Lance Barber) giving his football team a pep talk. In the speech he tells the team that even though they are probably about to lose he is still proud.

"You learn as much about who you are, and what you're made of from failing as you do from success. Maybe more. You can spend the next half feeling sorry for yourselves or you can get out there and give 'em hell!"

Sheldon recalls that day when the team lost really bad. He then says that the speech worked on him and he is determined to continue working on his research, thanking his dad for inspiring him to keep going.

"Thanks dad, we're going to give 'em hell," Sheldon says before he and Amy get back to work.

The Big Bang Theory airs Thursdays at 8 p.m. ET, followed by Young Sheldon at 8:30 p.m. ET on CBS.