get down and dirty

Translations
заняться грязной работой
During the investigation, the detective had to get down and dirty to find the truth.
Во время расследования детективу пришлось заняться грязной работой, чтобы узнать правду.
Definitions
To become actively involved in a task, often one that is difficult, messy, or requires hard work; can also refer to behaving in a bold, uninhibited, or sometimes risqué manner.
Words
get

verb
погрузиться
down

adverb
всерьез
and

conjunction
и
dirty

adjective
грязный