I heard her buy a ticket for Aleppo.

Can you imagine a lone, good-looking woman going to Aleppo by that train unless she had a laissez passe from the French?
She's wearing French heels.
I'll bet she's carrying secret information.

Look! D'you see those two Arabs in the train ?" He pointed out Grim and Jeremy, who were leaning from a window.

"They tipped her off to get into the compartment next ahead of them.

D'you see?
There she goes.