♪ That all started
with a big BANG ♪
The Big Bang Theory Season 7, Episode 14
♪ That all started
with a big BANG ♪
The Big Bang Theory Season 5, Episode 6
♪ That all started
with a big BANG ♪
The Big Bang Theory Season 12, Episode 20
♪ That all started
with a big BANG ♪
The Big Bang Theory Season 12, Episode 7
Previously on
The Big Bang Theory...
The Big Bang Theory Season 11, Episode 15