What did I realise?

For our last snippet in this lesson, let's stay in someone's head. 

I could tell from the way she looked at me.

Wonder(2012)

In this last snippet, we don't know what's going on. The character has noticed something, they've had a realisation—but we don't know what it means.

Let's try writing some examples that hint at someone realising something important.

I knew then that this day wasn't going to end well.

I finally understood what she wanted.

What has this kid just realised?

monsters disguised as humans in cinema
Bobby Chiu and Peter Chan

Write your own variation where someone realises something.