
♪ 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