Crucifix lane - Kate Mosse

Briefly unconscious after a fall in south east London's Crucifix Lane, Annie comes to and finds herself propelled eleven years into the future and caught up with a group of people, led by the charismatic Kellen, who are helping the disadvantaged. But Kellen's altruism is a cover for criminal activities including bio-piracy and Annie's friend Leah is a casualty of her refusal to face that fact. In a dramatic climax, Annie confronts Kellen as the Thames breaks its banks, and she is saved only by her return to 1997 - with the knowledge that London's future is in her hands.