be on the trail of somebody/somethingto be trying to find someone or something by getting information about them 在追踪[捕]某人/某物 industrial spies on the trail of technological secrets 盯上技术机密的商业间谍
Police believe they are hot on the trail of a drug-smuggling gang (=they are close to finding them). 警方相信他们正牢牢地跟踪着一个贩毒团伙。
be on the trail of somebody/something• Especially if you consider he was on the trail of the man he believes had his family abducted and almost certainly murdered.• He was on the trail of a stag, which turned to face him.• Cutler and Johnson are on the trail of the killer.• It had not occurred to her that the newspapers might still be on the trail of Puddephat's widow.
→ be on the trail of somebody/something at trail2(1)