The McCready sisters have just settled into their new home on Pine Island when they get word that an unwelcome houseguest is coming to visit for months.

"Clayton Stumper might be in his twenties, but he dresses like your grandpa and fusses like your aunt. Abandoned at birth on the steps of the Fellowship of Puzzlemakers, he was raised by a group of eccentric enigmatologists and now finds himself among the last survivors of a fading institution. When the esteemed crossword compiler and main maternal presence in Clayton's life, Pippa Allsbrook, passes away, she bestows her final puzzle on him: a promise...