Explorers
(Book)

"When a family goes to a local museum, a boy notices a homeless man sitting outside, making brightly colored origami birds. He convinces his dad to buy a bird the man makes just for him. Once inside the museum, his little sister takes the bird and launches it into the air. Is it lost? Soon another boy helps him look, and the paper bird brings two families--and two new friends--together" -- Amazon.com