I have recommended the Brambly Hedge series by Jill Barklem for ages. I have seen them go out of print and back into print again at least once. Yet, I have never read an actual book.
I found The Secret Staircase (pun not intended) while looking through some books that were (let us say) preloved. I picked it up thinking they were standalone stories. However, I quickly realized, while they are standalones, they do connect with each other and had I read a completed chronological collection that might have filled in the “incomplete” feelings I experienced at the ending. (Thankfully there is a complete collection that I will be looking into.)
I did enjoy The Secret Staircase despite any small issues I had. The story is a classic tale of a family of mice who are just like you and me, though they live in a community a little more self-sufficient and environmental then we might. And their clothing is a lovely Victorian era style. Perhaps it is not politically correct (the girl mouse is a tad bossy, but also the one afraid to explore) but at the same time, this could be set anytime (minus the clothing). It is just a story of being brave, finding secrets and celebrating family and tradition.
There are delightfully busy, colorful and sweet illustrations. They can be a bit overpowering at times, as there is just so much going on, but they are also perfect for the story. They show what you cannot get from the text. You can see the magic of the place the mysterious staircase leads as well as the fun the characters have during their holiday celebration.