When the crowd responded to the show so positively, we realized we were 'onto something'. [=we had done/discovered something important, special, etc.]
Scientists believe they are 'onto' something big. [=scientists believe they are close to making an important discovery]
Don't try to shift the blame 'onto' me. [=don't try to blame me instead of the person who should be blamed]
(..) Now, just step back inside. Come on. Step back inside so we can talk about this. We have talked enough. - Mal. - Come out onto the ledge... ...or I'll jump right now. - Okay. We're gonna talk about this. All right? - I'm asking you to take a leap of faith. (..)2010 Inception