The Graham Quartet and the Mysterious Strangers

In the midst of the cold, snowy woods, the Graham Quartet stumble across a mystery. It could mean danger, but that doesn't stop Elsa, Matt, Tim and Selena as they try their best to help a stranger who needs them. But what can Siam, Hong Kong and Vanderbilt have to do with the local furniture factory? And why are so many strangers suddenly appearing and then disappearing in town? With the arrival of an elusive figure, things start moving, while a simple delivery trip may bring more than the Quartet bargained for. Will the four siblings be able to help their friend and their country?