Maddie is sent on a scavenger hunt by Charlie! He says:
"Everything you need is in the pool house safe. The code... well, I've forgotten it. It's been years, after all. But I've hidden clues to that around the estate! Just follow them. I only remember the first one: ‘A sad heroine holds a key’”

Maddie understands that Charlie must have hidden something in the safe that will help Grandma! She decides to follow the clues - and knows just where to look first.