The first weekend of Millennium Docs Against Gravity – the prestigious international film festival in Poland – is underway after opening with Closure , the new film directed by Warsaw native Michał Marczak. The wrenching documentary about a father’s desperate search for his missing teenage son won the Golden Alexander at the Thessaloniki International Documentary Festival in Greece in March and premiered in World Cinema Documentary Competition at Sundance. Marczak’s journey to make the film began as he spent time on the Vistula River in Warsaw. While on a raft with his family – the director was scouting locations for a fiction project — he noticed a man plying the waters intently in a boat. After engaging him in conversation, Marczak learned the man, named Daniel, was looking for his son Chris who had last been seen standing on the Warsaw Bridge overlooking the river. Watch on Deadline ‘Closure’ MDAG “A rotating CCTV camera caught [Chris] there standing for 20 minutes.…