Pick up a tail from
To follow clues and info about something in order to accomplish something.
"Nelson, his wife Helen, and his associate John Paul Chase picked up a tail from the FBI in the town of Barrington, near Chicago. After a short chase, the two camps were picketed across from each other hurling bullets."
"I got to pick up a tail from this girl's heart with her friends. She is too much mysterious."
"I got to pick up a tail from this girl's heart with her friends. She is too much mysterious."