Mysterious Signal — Lois Walfrid Johnson

Danger lurks in the nighttime shadows!

When they learn that they are being watched, Jordan and his daddy need to leave Springfield, Illinois, at once. With the crooked Dexter behind bars, Libby, Caleb, Peter, and Jordan make plans to take the stolen money to its rightful owners. Then Dexter escapes! If he recognizes Libby, Jordan and Peter will be in great danger. A disguise is the only answer, but that requires a sacrifice Libby isn't sure she's willing to make.

Arriving in a strange city, Libby and her friends look for a safe house a station in the Underground Railroad where fugitive slaves can hide. But Caleb and the others don't know the area and finding help might be a matter of life or death. Can they spot a mysterious signal in time?