Cathy's friends, the Marling brothers, claim to have invented an unbreakable ceramic. One-Ten is interested and sends Steed to investigate. Steed enlists Cathy's help as it turns out she is in the midst of writing a book on fine china, anyway. But will a secret love affair, a scheming Dutchman from Leipzig, and a dead body found in a tank of clay turn into an unsolvable mystery?

I actually enjoyed this one. No location filming, but an excellent villain in Steve Plytas and you're left guessing until the end whether the unbreakable ceramic actually exists.

The shadow of the boom mike is plainly seen moving across Miller's torso in DeGroot's room.

Later on, the camera's shadow moves off the jacket of the waiter serving tea and cakes to DeGroot and Cathy.

The camera bumps into something and the scene erupts into an unmissable shudder as Miller scrutinises the unbreakable ceramic cup.

  - Courtesy of Wayne Beckett / Stay Tuned.

One-Ten: "But other people have been trying to make an unbreakable... plastic." (Should have been "unbreakable ceramic".)

Cathy: "They inherited the business from their bather."