be on the scent
be on the scent (of someone or something)
To be pursuing a potential lead in an attempt to find someone or something. With this new evidence, the detective thinks he's finally on the scent of the kidnappers.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
be on the ˈscent (of somebody/something)have information that will lead you to somebody/something: The police are on the scent of the criminals.
Farlex Partner Idioms Dictionary © Farlex 2017