back to the salt mines
Resume work, usually with some reluctance, as in With my slavedriver of a boss, even on Saturdays it's back to the salt mines. This term alludes to the Russian practice of punishing prisoners by sending them to work in the salt mines of Siberia. Today the term is only used ironically. [Late 1800s] Also see keep one's nose to the grindstone.
Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.