Mental health support is one of the greatest gaps in the global antislavery response. When slaves are freed but given no support to rebuild their lives, many slide back into slavery. We are therefore pioneering a unique programme of therapeutic care for people coming out of enslavement. A culture- and cost-sensitive mental healthcare support package for survivors will address slavery’s aftermath. We are designing protocols that can be shared across agencies and in the wider field. Survivors are co-designing the programme with us. We will then adapt these recommendations for cost-effective care within low-resource settings. At the same time we are working to understand perpetrator behaviour and reasons for offending. This extensive examination of offenders’ narratives and motivations will help us develop the evidence base for therapeutic interventions. By understanding slaveholders’ behaviour, and sharing that knowledge with the therapists we train, we will improve the quality of therapeutic care.