for Capture the Flag by Kate Messner
Three kids get caught up in an adventure of historic proportions! Anna, Josť, and Henry are complete strangers with more in common than they realize. Snowed in together at a chaotic Washington D.C. airport, they encounter a mysterious tattooed man, a flamboyant politician, and a rambunctious poodle named for an ancient king. Even stranger, news stations everywhere have announced that the famous flag that inspired "The Star-Spangled Banner" has been stolen! Anna, certain that the culprits must be snowed in too, recruits Henry and Josť to help catch the thieves and bring them to justice. But when accusations start flying, they soon realize there's more than justice at stake. As the snow starts clearing, Anna, Josť, and Henry find themselves in a race against time (and the weather!) to prevent the loss of an American treasure.
Publisher description retrieved from Google Books.