In Sweden, girl sleuth series in juvenile fiction appeared as a new phenomenon in the early 1950s. Deducing American influence, I compare the initial novel in the first series originally written in Swedish, Uno Modin’s Puck jagar en skugga (1951) with the first novel about Nancy Drew, Carolyn Keene’s The Secret of the Old Clock, launched in Swedish the year after. The analysis shows that although there are some basic similarities between the heroines, their contexts and agency significantely diverge. Also, whereas the Nancy Drew story is narrated in a fable-like manner, the Puck story has realist traits and a more advanced and ”literary” language. These differences, together with the post-war time context, help explain the immense popularity of the Nancy Drew novels in relation to the Swedish series.