 A young woman student from Indonesia is killed at an educational institute. Footprints at the crime scene indicate a large man was present. Five-O comes up with two suspects: her American boyfriend and a mentally challenged man, Benny Apa. Neither case is airtight. The boyfriend had an argument with the dead woman shortly before she died. Benny Apa confesses to the killing but McGarrett can t be sure if he knows what he is saying.