An offer of a free lunch even David Kershaw would decide to turn down?

Campaign doesn't have a public service remit but if it did, we'd be fulfilling it this week by publishing the following warning: no matter how desperate you are for a free lunch, make sure you've got a prior booking for Saturday 23 August.

There's a bit of a scary invite doing the rounds and it's coming from Michael Conrad, the former global creative chief of Leo Burnett who wants to "show his creativity in a new, different way".

The Conrads, apparently Switzerland's equivalent of the Brady Bunch, are hosting a "slow shovel lunch" (whatever that is). An e-mail being sent to invitees explains how Michael, his daughters Anja and Josepha, son Philip and wife Helga are preparing the feast.

It reads: "We will prepare food that is cooked in the earth, that takes time, that gets hands dirty, that leaves you with anxious mouth. And while the meat tenders with the hours, we let the muses amuse us. We will collect words and ideas, will exchange songs and images, will steal things from one another and tell stories. We will create glue that sticks to threads of conversation from person to person."

According to the invitation, the matriarch of the Swiss Family Conrad will be in charge of "creative spices". Helpfully, the e-mail also informs us that Helga is 57.

There is something extremely odd about the whole affair. You have been warned.