This week, Brooke talks to Christo Grozev, lead Russia investigator with Bellingcat, about how he uncovered the real identity of a Russian "sleeper" agent who went by the name Maria Adela. Grozev tells Brooke about how rarely these kinds of spies are discovered, what made "Maria Adela" an unlikely spy and what kind of information she could have gathered on NATO.

On the Media is supported by listeners like you. Support OTM by donating today (https://pledge.wnyc.org/support/otm). Follow our show on Instagram, Twitter and Facebook @onthemedia, and share your thoughts with us by emailing [email protected].