The Pikes' foreign neighbors move into the house behind the Pikes in #13, Good-bye, Stacey, Good-bye. They have a "long, funny" last name and speak with a strong accent, which Mallory imitates thusly: "'ow nize do meed you. Thank you zo moch for your 'ozpeetaleetee."
The Pike kids assume that their new neighbors are foreign spies, leading Jordan Pike to invent the game Secret Agents. Through their reconnaissance missions, the Pikes discover that the new family's den is filled with high-tech equipment: "a Xerox machine, a Telex machine, two computers, a printer…" When Claire Pike rings the doorbell and hides, a woman with extremely long dark hair comes to the door. They also record someone saying that "courgettes" would be served for dinner; Nicky suggests that "courgettes" could mean "children," inciting panic until Mallory, showcasing the cool-headed collectedness that would later make her an accomplished member of the BSC, checks a cookbook and finds that the word is French for zucchini.