Marcus Sedgwick's Floodland is his gripping first novel.
The dramatic opening:
Zoe ran. Harder than she had ever run in her life. Her feet pounded through the deserted streets of derelict buildings. Somewhere, not far behind, she could hear the gang coming after her. It felt as if her heart would burst but she didn't slow down. She'd been planning to leave the island for a long time but had been putting it off. It was a big decision to set out to sea in a tiny rowing boat. Now she had no choice.
Sets the scene remarkably well. This tale is set some time in the not-too-distant future in an England that has been almost wholly reclaimed by the sea. Young Zoe last saw her father and sick mother as they sailed away on the last boat from Norwich, leaving Zoe to face the future alone. one day, though, she finds a small rowing boat, and after some labour she manages to get it seaworthy and to find some oars (in a pub) with which to leave Norwich. She makes her way to Eel Island (Ely Cathedral and its immediate environs), a place where a strange boy named Dooby rules, despite his youth, and an old man named William tells mystifying stories, including a half remembered tale about a Doctor who went somewhere and stepped in a puddle and never went there again. William's actually half-remembering this rhyme:
Went to Gloucester
In a shower of rain.
He stepped in a puddle
Right up to his middle
And never went there again.
He also vaguely remembers the story of Noah and his Ark, and he tells Zoe of the days before England and the world was flooded, when it was possible to drive from Norwich to Ely Cathedral. This is a world that Zoe knows nothing about and can scarcely believe in.
Unfortunately for Zoe, Dooby wants Zoe to take him away from Eel Island in her boat and he hides it from her, or rather his chief henchmen, Sprat and Munchkin, hide it somewhere. Dooby fits an outboard motor to it and plans that they will go off together in the next few days. Before Dooby can carry out his plan, however, a boy from a mob on some nearby island is discovered spying on the Eels. Dooby discovers that the boy's mob, the Cats, intend to invade Eel Island. When the invasion begins, he insists that Zoe help him escape. Unfortunately for Dooby, he failed to realise that outboard motors require petrol to function, and he also failed to discover the whole of the Cats' invasion plans. In the end, Zoe makes good her escape, not with Dooby, but with Munchkin, whom she had befriended whilst trying to find out where Dooby had hidden her boat. Despite almost drowning, the pair manage to reach the mainland of England, or what's left of it by now, and they go in search of Zoe's parents, although Zoe knows they may not have survived the journey, especially when her mother was sick.