The aim of this study is to determine whether it is feasible to complete a pilot trial of Multi-Systematic Therapy-Exploitation (MST-E) within existing Multi-Systemic Therapy (MST) services in England. MST-E is an adaptation to the standard MST delivery protocol with a focus upon attempting engage families where there is a child at risk of criminal exploitation. We will investigate the feasibility of MST-E within two phases. Phase 1 will involve finalising a logic model with our delivery partners to describe the additional components of MST-E and will involve holding a series of focus groups with clinicians, stakeholders, families and young people to further refine MST-E and associated tools. Phase 2 will be a single-group modelling study with 50 families who have been referred for MST-E. We will examine (i) the acceptability and feasibility of MST-E for stakeholders, including families, (ii) patient and clinician satisfaction with the intervention, (iii) the appropriateness of our measures in terms of their use within a future pilot trial, (iv) the appropriateness of an adapted fidelity checklist, (v) the accrual rate and willingness of teams to recruit participants, (vi) therapy completion rate and attrition, and (vii) the within-group effect size. As part of this, we will complete in-depth interviews with 12 families (6 who have successfully completed treatment, and 6 who have discontinued treatment, but have consented to take part in our interview) and 12 clinicians to further investigate acceptability.