In The Samurai and the Prisoner, the new historical mystery set in feudal Japan, the biggest puzzles are hidden in plain sight. Maybe that is why he keeps the wily Kanbei, who is always thinking three steps ahead, as his prisoner. Like FX’s recent Shōgun series, The Samurai and the Prisoner is full of rich imagery and period detail. The pleasure of Kurosawa’s film is how he synthesizes a beloved genre into something new, going across continents and oceans for his influences. The Samurai and the Prisoner (R, 147 mins.)