When the cameras panned to the audience during Barack Obama's final speech as President of the United States, plenty of people noticed one thing in particular.
Obama's wife Michelle and elder daughter Malia were watching on, but there was no sign of Sasha, the younger of the two Obama sisters.
As soon as people noticed her absence, questions were asked.
https://twitter.com/iconicbesh/status/819014851540480002
https://twitter.com/OmbiroJane/status/819034769942048768
https://twitter.com/Peachypink_1d/status/819022530463825920
Not to mention the speculation about what we'd see in the light of her absence.
https://twitter.com/ashwindeshmukh/status/819013074216697856
However, as is often the case, there was a perfectly reasonable explanation for it all.
It's exam season at Sasha's school - Sidwell Friends School, where her sister was also a student - and the 15-year-old had to stay home and study.
https://twitter.com/markknoller/status/819037199379394560
There we go. Mystery solved.