回歸正題 的英文怎麼說?

A: My book report is on "A Tale of Two Cities written" by Charles Dickens. Oh, speaking of Charles Dickens, he's one of my favorite authors. I used to read his novels growing up. One day...
B: Let's get back on track, buddy. Focus on your book report.
A: Oh yes, sorry, so this novel is set in London before and during the French Revolution...