Best of Friends - Kamila Shamsie
 
Maryam and Zahra.

In 1988 Karachi, two fourteen-year-old girls are a decade into their friendship, sharing in-jokes, secrets and a love for George Michael. As Pakistan's dictatorship falls and a woman comes to power, the world suddenly seems full of possibilities. Elated by the change in the air, they make a snap decision at a party. That night, everything goes wrong, and the two girls are powerless to change the outcome.

Zahra and Maryam.

In present-day London, two influential women remain bound together by loyalties, disloyalties, and the memory of that night, which echoes through the present in unexpected ways. Now both have power; and both have very different ideas of how to wield it… Their friendship has always felt unbreakable; can it be undone by one decision?