on the scent
on the scent (of something)
1. Literally, of an animal, in pursuit of its prey or quarry by following their scent. They put the bloodhounds on the scent of the escaped prisoners.
2. In keen pursuit of some object or goal. With the explosion of the internet and mobile devices, many young graduates are on the scent of lucrative careers in programming and web design. Don't worry, when Janet's on the scent, she always secures a sale.