Over the last two decades, fighting modern slavery and human trafficking have become a cause célèbre. Yet, large numbers of researchers, nongovernmental organizations, trade unions, workers, and others who would seem like natural allies of the fight against modern slavery and trafficking are hugely skeptical of these movements. They object to anti-slavery and anti-trafficking framings of the problems, and are skeptical of the "new abolitionist" movement. Why? In this Introduction, we explain how our edited book tackles key controversies surrounding the anti-slavery and anti-trafficking movements and scholarship head-on. We have assembled champions and sceptics of anti-slavery to explore the fissures and fault-lines that surround efforts to fight modern slavery and human trafficking today. These include: whether efforts to fight modern slavery displace or crowd out support for labor and migrant rights; whether and to what extent efforts to fight modern slavery mask, naturalize, and distract from racial, gendered, and economic inequality; and whether contemporary anti-slavery and anti-trafficking crusaders’ use of history are accurate and appropriate.