The sacred art of stealing - Christopher Brookmyre

The second book in the Angelique De Xavier series, from author Christopher Brookmyre.

Their eyes met across a crowded room.
She was just a poor servant girl and he was the son of a rich industrialist.
Er, no, this is a Christopher Brookmyre novel, although the eyes meeting across a crowded room part is true.
Where it differs from the fairy tales is that the room in question was crowded with hostages and armed bank-robbers, and his eyes were the only part of him she could see behind the mask.
He is an art-thief par excellence and she is a connoisseur of crooks.
Her job is to hunt him to extinction; his is to avoid being caught and he also has a secret agenda more valuable than anything he might steal.
There are risks he can take without jeopardising his plans.
He can afford to play cat-and-mouse with the female cop who's on his tail; it might even arguably be necessary.
What he can't afford is to let her get too close:
he could could end up in jail or, even more scary, he could end up in love ...