We here begin considering whether we can evaluate that the implementation work undertaken in M contributed significantly to correct Signs of Safety practice with families, and with what warrant. We first amplify the organisational Theory of Change by constructing a boxes-and-arrows theory of change representing the operation of the various causal pathways involved in implementation in M. We then use our expanded approach to modelling causal pathways in fuller detail on one pathway, L, involving the introduction of new ‘collaborative case audits’, laying out the activities involved, tendency principles, support factors and detractors and weighing up the available evidence to warrant the claim that this innovation contributed to better use of Signs of Safety methods with families.