“This is a Bulgarian umbrella; have you heard about this one?” Agne Urbaityte asked, pointing to a blue umbrella behind a glass case. There was a needle peeking out from the top.

“It’s a weapon umbrella,” she said. “You press the button here, you see the needle, the needle goes out and shoots a small shot of ricin poison. It’s still the most harsh poison in the world .”

Thank goodness this was not the real thing. It was the kind of tool famously used to kill the Bulgarian dissident author Georgi Markov on Waterloo Bridge in 1978, roughly a decade after he defected to the West. Many have speculated since that the K.G.B. was involved .