2명의 어린 소년 소녀가 할머니 집에 방문하지만, 할머니는 온데간데 없다. 할머니를 찾다가 바닥에 동물의 발자국이 찍혀있고 할머니 집에 새로 생긴 창문이 조금 열려있는 것을 발견한다. 호기심에 못이긴 아이들은 기어서 그곳을 통과하고 낯설고 환상적인 세계로 들어서며 모험이 시작된다. 사라진 할머니를 찾는 것을 계속하며 곳곳의 수수께끼를 풀어나가는 아이들은 한국 전통문화에 대해 더욱 깊이 들어가게 되고, 곳곳에서 많은 캐릭터들을 만나고 한국의 문화유산에 대해 더 많이 알게 된다.

Beautifully illustrated and told by debut author Julie Kim, this picture book in a graphic-novel style follows a young Korean girl and boy whose search for their missing grandmother leads them into a world inspired by Korean folklore, complete with mischievous goblins (dokkebi), a greedy tiger, a clever rabbit, and a wily fox.
 
Two young children pay a visit to Halmoni (grandmother in Korean), only to discover she's not home. As they search for her, noticing animal tracks covering the floor, they discover a window, slightly ajar, new to their grandmother's home. Their curiosity gets the best of them, and they crawl through and discover an unfamiliar fantastical world, and their adventure begins.  As they continue to search for their grandmother and solve the mystery of the tracks, they go deeper into a world of Korean folklore, meeting a number of characters who speak in Korean along the way, and learn more about their cultural heritage. 
 
This beautifully illustrated graphic picture book is filled with a number of Easter eggs for readers of all ages to discover, and is inspired by the Korean folktales that author and illustrator Julie Kim heard while growing up. Translations to Korean text in the story and more about the folktale-inspired characters are included at the end.