The SOLE clue:
"It's not what it looks like."
The Big Bang Theory Season 5, Episode 1
...whose daughter, Lakshmi, Is flying In
for the SOLE purpose of meeting him.
The Big Bang Theory Season 3, Episode 7
He’s going to sue me
for SOLE custody of my daughter,
Money Heist Season 1, Episode 8
Cersei believes
my SOLE purpose in life
Game of Thrones Season 7, Episode 3
I'm the SOLE author
on a paper being published
The Big Bang Theory Season 5, Episode 12