In the spring of 2022, Lithuania heard startling news: a turning point in the country's photographic history. An exhibition at the National Museum of Lithuania revealed a never-before-heard photographer whose negatives had been languishing in the museum's archives for over 80 years! As in the story of the American photographer Vivian Maier, this discovery was made by chance. It all started when a museum archivist decided to tidy up long-abandoned negatives that had been uncatalogued since 1948. The name "Ingelevičius" and laconic descriptions such as "street of an unknown city" were all the information recorded in the archive catalogues. She entrusted the negatives to the museum's photographer, who saw the artistic value in the contact prints and began producing large exhibition prints. An archaeologist joined in the discovery and saw in the photographs images of a long-lost wooden Kaunas. This was the start of a historical investigation and a gripping, visual detective story. "Archives Detective is a documentary that invites you to explore the incredible story of the discovery by the museum staff. The audience witnesses this lively investigation, guided through the labyrinth of the archives, where the past only comes alive through patience and foresight.