A Matryoshka doll also known as Russian nesting/nested doll, refers to a set of wooden dolls of decreasing size placed one inside the other.
Detective John Kennex was given a set of these dolls by his ex-girlfriend, Anna Moore, as a gift. He kept it on a shelf in his apartment, until he kept getting flashbacks highlighting the doll. He checked it over himself, and could find nothing suspicious about it. He took it to the CSI laboratory to be tested by CSI McGinnis. The testing revealed that the doll had a listening device embedded into the paint via nano-circuitry and the last upload had been seven hours ago.