Melmoth by Sarah Perry is gripping and beautifully written. Helen Franklin has been living an ascetic life in Prague for twenty years. She has literally two friends, one of whom comes into possession of a manuscript describing a “witness," who according to legend wanders the earth looking for people who have participated in history’s darker events. There are a number of interwoven stories spanning 500 years. Each touches on the power of guilt and whether restitution is possible in order to change one's future. This is a fascinating book that will stay with you long after you finish.