Helena has a secret that she shares with her grandparents. Every Tuesday during the school holidays she spends the day with them and if the date of that Tuesday happens to contain a seven, she knows she's in for a magical time.When Helena is set a school project for the summer holidays, she looks at the calendar and realises that a certain Tuesday can help her complete it.This is the first in a series of Helena Eaves adventures that will both entrance and educate younger readers.