It doesn’t take a detective to figure out that The Aftermath is another Keira Knightley paycheck movie, a post-war period piece where the actress wears tailored cardigan sets and cries in bathtubs and has an affair with a man taller than her husband. But, isn’t that the dream? A James Kent-directed adaptation of a Rhidian Brook novel by the same name, The Aftermath is far from a great film, so deeply mired in genre conventions that playing a period piece drinking game while watching would have you in an ambulance within the first half-hour. But it’s much too fun and visually interesting to get angry about, especially when compared to other recent Knightley vehicles like Colette. Here, the actress and her famous jawline star as Rachael Morgan, an Englishwoman who is grieving the death of her son and is reunited with her colonel husband Lewis (Jason Clarke) in Hamburg during the winter after the Allied victory. When the pair move into a lovely estate with a grand piano and a Bauhaus chaise lounge, Rachael is shocked to find that her forgiving husband has allowed its German owners, widower Stefan Lubert (Alexander Skarsgård) and his quiet daughter Freda (Flora Thiemann), to remain in the house with them. Enmity quickly turns to attraction and, before you know it, Rachael and not-a-Nazi Lubert are having sex on the dining room table while Col. Morgan is off “saving Germany.” The Aftermath tries to say something interesting about guilt and complicity but ultimately whiffs (hey, it’s no Atonement). At least it gives us some beautiful knitwear and genuine intrigue while trying. At Kendall Square.