onto (something)
1. Having knowledge, suspicions, or awareness of something deceptive or underhanded.You'd better tread carefully—I'm onto you now.The police are onto us! Everybody run!
2. Discovering, realizing, or in the process of doing something of great importance, value, or insight.Great work on this essay, Lindsay. I really think you're onto something here.Scientists now believe they may be onto a cure for cancer.
onto something