While vacationing at a friend's country home, the four Alden siblings try to find a long-missing, priceless brooch and investigate the existence of a ghostly stream.
When they take their dog, Watch, for obedience training, the Alden children discover that some of the dogs in the class have vanished and decide to try to solve the mystery of their disappearance.
The Aldens try out a Halloween escape room. The puzzles are fun to solve, but when eerie events start scaring people away, the children find a much bigger case to crack.