THEN THERE WERE FIVE by ELIZABETH ENRIGHT

 THEN THERE WERE FIVE by ELIZABETH ENRIGHT Pgs 260

With Father in Washington and Cuffy, their housekeeper, away visiting a sick cousin, almost anything magic might happen to the Melendy kids left behind at the Four-Story Mistake. In the Melendy family, adventures are inevitable: Mr. Titus and the catfish; the villainy of the DeLacey brothers; Rush's composition of Opus 3; Mona's first rhubarb pie and all the canning; Randy's arrowhead; the auction and fair for the Red Cross. But best of all is the friendship with Mark Herron, which begins with a scrap-collection mission and comes to a grand climax on Oliver's birthday.

I re-read this every few years.