φθάνω το μαχαίρι στο κόκκαλο → get to the root of the problem, follow the issue no matter where it leads, go the whole hog, leave no stone unturned, bring matters to a head, be hard-hitting, get to the bottom of, get to the bottom of the matter, sort out by hook or by crook, take to the highest level possible

[spiros]

φθάνω το μαχαίρι στο κόκκαλο → get to the root of the problem, follow the issue no matter where it leads, go the whole hog,  leave no stone unturned, bring matters to a head, be hard-hitting, get to the bottom of, get to the bottom of the matter
φθάνω το μαχαίρι στο κόκαλο