The Secret of the Wooden Witness — George Edward Stanley

ATTACKED!
Someone knocked out Todd and Noelle's friend Pops Verner, the night watchman at the department store, and stole his treasured pocket watch. He's pretty sure the robber is one of three men who work in the storeroom. But how can he figure out which one, when the only clue is a carved wooden figure the thief left behind?

It's a new case for Mr. Merlin's Third-Grade Detectives. But can the Detectives solve the mystery when Mr. Merlin himself is missing?