The Haunted Cabin Mystery — Gertrude Chandler Warner

One warm night four children stood in front of a bakery. No one knew them. No one knew where they had come from.

Henry, Jessie, Violet, and Benny used to live alone in a boxcar. Now they have a home with their grandfather and are going to visit his friend, old Cap Lambert, a retired riverboat pilot who lives in a cabin in the woods.

To get there, the Boxcar Children take a wonderful trip down the Mississippi in a paddle-wheel boat. But when they arrive at Cap Lambert's cabin, they find some mysterious things are going on. Spooky phone calls, eerie flickering lights, strange dark figures. Is the cabin haunted?