There's not a lot of sweetness and light to recommend this weekend, but if you are in the mood for a walk on the dark side, two films call out from the abyss. "The Silence" is an exemplary German-language thriller in which the crime under investigation is the rape and murder of young girls. An impressive feature debut by writer-director Baran bo Odar, this is a complex and disturbing examination of guilt, violence and psychological torment that chills to the core. Just as accomplished but quite different in tone is Kim Nguyen's "War Witch," an examination of two violent years in the life of an African child soldier that is potent enough to be one of the five nominees for the foreign-language Oscar. What is unexpected about this film is its sheer artistry, in terms of filmmaking skill and the acting ability of young Rachel Mwanza, who is so impressive she became the first African actress to win the Silver Bear at the Berlin Film Festival. There's not a wasted moment in either film.