My girlfriend was studying the Radio Times. “Did you know Agatha Christie lived nearby?” she said. “In a mews house on 22 Cresswell Place in Chelsea. You know what? Cresswell Place is only a step from here. Tomorrow we’ll walk there.” “You must be joking,” I said. “Aren’t you excited?” On the ivy-covered, white-painted brick wall a blue ceramic plaque marked the previous owner’s identity. The plaque AGATHA CHRISTIE 1890-1976 Author and playwright lived here. 22 Cresswell Place was on the market for a little over £2 million. “You’re such a lucky man,” my girlfriend said. “Am I? Why is that?” “I’m going to buy this place.”