James Darrell is known to be "blunt and abrupt". He has been living in India for many years but is now returning to England. Soon after arrival, he presents his nephew, "Bunny" Darrell, with a very special ring. Unknown to Uncle Darrell or anyone else, whoever possesses the ring is incapable of telling a lie, however small. Ever-polite Bunny soon is creating difficulties everywhere he goes. As the Darrells and their friends slowly uncover the cause of the truth, they learn that congenial society is only possible thanks to a lot of social conventions that don't adhere strictly to the truth