From Edgar Award Winner Dori Hillestad Butler comes The Treasure
Troop, a chapter book mystery series! Join Marly, Sai, and Isla, three
code-cracking kids on the hunt for an old neighbor's hidden treasure.
In the fourth and final book of this code-busting series, Marly, Sai,
and Isla are back on the hunt. After their shocking discoveries on
Summer Island, the Treasure Troop has one final set of clues to follow
before reaching the end of their search. And now our trio must solve the
toughest mystery of all: what really happened to Mr. Summerling?