A retired couple pay the price when their tenants stop paying rent and invite their abusive friends in to squat. A man can't sell his house because his sitting tenant refuses to leave. Harrow Council housing officers visit a vulnerable family living in damp and squalid conditions.

When Harrow Council carry out early-morning raids on several dangerous properties they find vulnerable tenants paying through the nose to live in uninhabitable conditions, including one man living in a plywood shed on the roof of a building.