Who ruined Leonard, Sheldon and Wolowitz's top-secret military project?
That was one of the bigger questions on The Big Bang Theory Season 10 Episode 23 when they celebrated the successful completion of the project.
However, someone decided it was time to make them pay for a past mistake.
Meanwhile, Amy considered an offer of a summer position as a visiting researcher.
How did this go down with her nearest and dearest?
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Paul Dailly is a staff writer for TV Fanatic. Follow him on Twitter.