Mary thought for a moment and then said, 'I think I know the answer to the riddle.' She whispered the answer to Benny, and the door creaked open, revealing a hidden room inside the tree. Inside, they found a chest filled with glittering jewels and a note that read, 'For the bravest and most curious of hearts, this treasure is yours to keep.' Benny said, 'You did it, Mary! You saved the garden!'