Working from the oldest group of children to go missing to the newest, draw a line in order of their listed names on puzzle 10 to the matching carriages on this page.

For example, the oldest missing poster (1842) lists these five children in order: Michael, Thomas, Penny, Lucy, and Oliver. On the Ferris wheel, draw a line from Michael's carriage to Thomas carriage to Penny, then Lucy, and finally Oliver. You will see you've drawn a number 3. This is the first of your 3 digits for your code.