That is when Stuart Landsborough's Puzzling World, in Wanaka, unveils its new collection of illusions.
Sculptors in Wanaka, Invercargill, Motueka and Wellington are putting the finishing touches to more than 18 new illusions that have been planned for the last five years.
Four of the illusions are being created by Wanaka metalcrafter Ernie Maluschnig.
They include a shiny metal ball that will seemingly travel up a spiral, a cube that appears to turn inside out and a collection of large nuts that seem to bend straight lines.
Mr Maluschnig revealed the almost completed illusions to the Otago Daily Times this week.
He said he had enjoyed turning ideas and two-dimensional drawings into large three-dimensional objects that worked as illusions.
With 40 years' experience shaping metal, Mr Maluschnig said his interest had always been in using his metalwork skills artistically.
He was confident of meeting his mid-November deadline but expected there would be a few late nights.
Puzzling World marketing manager Duncan Spear said the majority of illusions were being made by four local sculptors whose work was known to be a "little bit outside the box".
In some cases he had given the sculptors merely a verbal brief or a picture of what was required and they had created a model to ensure the illusion worked and then begun a full-size version, Mr Spear said.
"It's a real trial to see if the illusion is as strong when it's a sculpture in larger form," he said.
The new collection of illusions is the biggest addition to Puzzling World since 2001.
