I ran my tongue between my lips and up across the tips of my moustache, tasting the salty residue of my last mouthful. "For sure, you grilled the sweetbreads to perfection, and this jus is divine." I batted my eyelashes at Derek, opposing me across the dining table. "My darling, you simply must give me the recipe."

He smiled as he dabbed each corner of his mouth with a lacy napkin. "The secret, my dear, is in the sourcing of the ingredients." He swept a hand to indicate the spread of dishes steaming between us, covering the table like a smorgasbord of edible blossoms. "Everything here is garnered from a single place, and every part is used - no waste. At Consumption Club, we practice snout to tail cooking."

A round of polite titters filled the air. Eight guests - all dressed to the nines, but other than their attire, an astonishingly diverse bunch. I watched them all eat for a few moments and took in the sensations; cutlery and lips glossy with grease, eyes closing in contentment, the occasional appreciative 'mmmm' sound, and the hopelessly glorious aromas of scratch-cooked fine dining.

"Pray tell," I said, taking a sip from my full-bodied red, "what is the single source on this occasion?"

Derek sucked a spoon of veloute sharply into his mouth and let a sigh expand his nostrils, eyes closed, apparently in euphoric enjoyment. "Today, we are enjoying a Spanish import - tapas style!" He swept a curled arm above his head in what was probably intended to be a Flamenco move. After a couple of breaths, he finally opened his eyes and matched my gaze. "Are you enjoying your first time?" He licked his lips. "It can be challenging, the first time."

I squeezed my eyes slightly in response - not quite a wink, but friendly. "I'll admit, I'm not used to such rich delicacies." I spooned some fried potatoes, slick with vibrant sauce and discs of meat, onto my plate, noting the warm sharpness in my nose. "This one, I recognise - Bravas!" I swept a forkful into my mouth.

"Made with our own special recipe." He was watching me intently and I couldn't tell whether he was flirting or suspicious. It was as our eyes met again, his squeezing like mine had, smile wrinkles settling and pulsing above his cheeks, that my questing tongue met something I'd been dreading. My instinct was to stop instantly, but I couldn't while he was watching me. Instead, I shuffled the object into the mushed potato in my mouth, chewed once, and swallowed. His green eyes bored into my soul.

"Simply fabulous, darling," I said, breaking his gaze and lifting my napkin for a dab. Something heaved in my stomach. At last, I had what I needed. I slipped a hand into my trouser pocket and pressed a button on my phone.

"A toast!" said one of the other guests, raising their glass high. We all followed suit. "To Consumption Club!"

"Rather!" chorused the voices as we all took sips.

Derek laughed and addressed the table. "Would anybody like some more fava beans, or a top-up of Chianti?" Everybody fell about giggling and he waited for the laughter to subside. "I'm sorry, I know I make that joke every time, but we are nothing if not creatures of tradition!"

"Hey!" came another chorus, garrulous and merry, glasses hoisted aloft. I followed suit, focusing on the noise, ignoring the sensations in my throat and stomach.

"Once more," he said when the noise subsided. "To our Spanish import - to tapas!"

We all cheered and stamped our feet on the floor and drank again. It was with great relief that I heard a knock at the door, and the whole table went as quiet as a mausoleum.

"Huh?" said one guest. "Who would interrupt us?"

I watched Derek's eyes tighten and waited for the penny to drop. It didn't take long - his head snapped round to settle an expression of intense betrayal on me. "Tell me, my dear," he whispered. "Do you have a little secret?"

I shrugged. "You made a mistake, darling. You see, your Spanish import," I swept my hand to indicate the table, as he had previously, "happens to be the son of Spain's diplomat here in London. He was here to visit his family."

The knock sounded again, more insistent. "Met police! Open up now, or we're coming in by force."

The other guests stood, filling the air with sounds of alarm, but there was only one doorway. Derek remained glued to his seat, pinioning me with his gaze. He knew there was nothing to do but wait for the inevitable.

"Detective Sergeant Hanton, at your service," I said. "We've been hearing rumours of your little club for some time now. It's just blind luck that you happened to choose the wrong victim."

He blinked. "How did you know?"

"I wasn't completely sure, until that last mouthful. You see, the victim had many piercings, and he used a uniquely shaped push-back. Now, I'm not sure which one your chef missed when he was making that Patatas Bravas, but now I'm certain those discs of meat weren't Chorizo." My stomach lurched again. "I never knew how dedicated I was to the job, until now."

The door burst in with a percussive crash, closely followed by a procession of uniforms. Derek never broke eye contact with me as his arms were cuffed behind him and rights read.

"I only want to know one thing," he said beseechingly. "How was it - did you enjoy your meal?"

And with that, I leaned to one side, sent a mental apology to the victim, and plunged two fingers deep into my throat.