Tess is a 12-year-old girl who has never met her dad and her mum refuses to say who he is. But Tess is determined and resourceful and not only discovers his name, but she invites him to come and stay (without her mum knowing)!

The story is told by Sam who is on holiday on the island of Texel with his family. He sees things differently from other people and he and his brother don't always get on. Sam wonders what it would be like to be the only person left in the world...

Playing on the beach, Sam's brother hurts himself and a visit to the doctor and then a referral to the hospital follow. But in the process Sam meets Tess who is keen to have a new friend alongside her as she carries out her plans for a summer to remember.

Tess's father doesn't know she exists and she has secretly arranged for him to visit the island so that she might get to know him, and he might want to get to know her. 

She has arranged all sorts of activities for her dad to do, without anyone except Tess being aware of what's going on. But Sam is let in on the secret and when things don't go as well as Tess had hoped, he feels he has to step in to help.

It seems an unusual idea for a children's book (aimed at 10-14-year-olds) but it works and it's funny and charming. It's written by an award-winning Dutch author and has been a bestseller in The Netherlands and Japan, and a 2019 film of the story has also been a big success.