The Giant Yo-Yo Mystery (The Boxcar Children Mysteries #107)
By Unknown Author.
Description
The Aldens are helping one of Grandfather's friends break a world record by building the world's largest yo-yo! But someone follows them, and then the plans for the yo-yo turn up missing. Someone is trying to sabotage the yo-yo before it's launched! - from Amzon
ISBN(s)
0807508780, 9780807508787
