“But you don’t understand,” Florence replied. “It isn’t exactly proper for me to wander down that back street.”

Both girls opened their eyes wide in astonishment.

“Not proper to go back of your own house!” ejaculated Peggy. “The very idea!”

“Yes, you see it’s only a narrow street leading to one of the poorest sections of the city. Only the very lowest class of people live on it. Mother and I drive down on the next street sometimes, accompanied by Felipe, to carry food and clothes to the destitute families, but I’ve never been down that narrow street.”

“It must be something like it is on the street cars at home,” Jo Ann said thoughtfully, coming to Florence’s assistance. “You know how they are, Peggy—one section marked ‘Colored,’ and you never sit there.”

Up the long flight of stairs they ran to the Blackwells’ apartment, each girl eager to be the first to solve the mystery. Jo Ann’s long legs carried her ahead of Florence and Peggy, who arrived a moment later out of breath.

There stood Jo Ann staring blankly at the solid plastered wall at the end of the hall.

“I’m sure this is where that window ought to be,” she said finally in a perplexed tone.

“There certainly isn’t any sign of one that I can see,” added Peggy, while Florence gazed silently at the spot where she thought the opening should be.

Just then Juana ran in from the kitchen to see what had caused so much commotion in the silent old house. “Florencita! Que es [What is it?]?” she asked in alarm.