Four good liars

Four teenagers.
A terrified older sister. A troubled surfer. An insecure genius. A spoilt brat.
They have nothing in common, except for two things. They all have shameful secrets. And they all desperately need money. So when a strange school bus accident puts a bag with a million pounds in cash into their hands, they make a pact. They’ll keep the money and tell no one. And no one will notice. Right?
But then someone starts coming after them, and they have no choice but to stick together. But can they manage something like that when every one of them is a first-class liar?