be on the trail of somebody/something
to be trying to find someone or something by getting information about them

[TahlilGaran] Dictionary of Contemporary English ▲

on the trail of something
• on the trail/track of (someone or something)
to be seeking someone or something
The police dogs were on the trail of the man who had robbed the bank.

[TahlilGaran] English Idioms Dictionary ▲

on the trail of
Hunting or looking for; trying to find; following.
The hunter is on the track of a deer.

The lawyer is on the trail of new proof in the case.

Jim collects old stamps; he is on the track of one in Midville this afternoon.

See: ON THE TRACK OF.

[TahlilGaran] English Idioms Dictionary ▲

on the trail of someone
• on the trail/track of (someone or something)
to be seeking someone or something
The police dogs were on the trail of the man who had robbed the bank.

[TahlilGaran] English Idioms Dictionary ▲