get to the bottom of

/G EH1 T UW0 DH AH0 B AA0 T AH0 M AH0 V/
verb
  1. 1

    To come to understand, discover the truth about, or solve.

    โ€œI don't know what's going on here, but I'll get to the bottom of it sooner or later.โ€

Source: https://en.wiktionary.org/wiki/get%20to%20the%20bottom%20of