Ingo tetralogy
The Ingo tetralogy is a series of four children's novels, set in Cornwall, by British author Helen Dunmore. The four books are, in chronological order, Ingo, The Tide Knot, The Deep and The Crossing of Ingo. The first book was nominated for the 2008 Booktrust Teenage Prize.
There are 4 books in this series, written by Helen Dunmore.