The ‘ingenuity’ of dealings which can arise when a person is faced with a desire to raise money is amply demonstrated by Kensington Mortgages v Mallon. The result of the careful judgment of Sir Gerald Barling (in an appeal from the County Court) is without fault. But the reasoning shows that the conceptual ambiguities in the Land Registration Act 2002 (LRA 2002), and in the fundamental structures of land law, continue to produce challenges in practice. Issues around sufficiency of pleadings, constructive trusts, estoppel, formality rules, priorities, and mistake are all addressed. Most difficult, is the analysis of the interaction between the owner’s powers and the priority provisions, in sections 23, 24, 26, 29 and 30 of the LRA 2002. The case prompts us to question, in particular, where lies the boundary between validity and value; between estoppel and trusts; and the role of formalities.