A stranger to a trust can be made to answer for the whole loss if they lend a dishonest hand to the breach. This chapter sets out the four elements of the claim and its personal, fault-based character, then examines which trust and fiduciary relationships qualify and what counts as assistance — including how much causal contribution is needed and whether passive knowledge is enough. It works through the objective test for dishonesty, before showing how that standard applies to wilful blindness and to professionals such as solicitors and bankers. It closes with apportionment between the assistant and the defaulting trustee, the remedy of equitable compensation, and the distinction between dishonest assistance and knowing receipt.