I walked in to browse- something always dangerous to do with bookstores. I fell for the trap of…read morethis store like a fish swallowing hook, line, and sinker. The collection was enormous. There were plentiful books in English, French, Norwegian, etc, both rare/antique and slightly newer.
The most impressive was the selection. I thought there were already a lot of books on the ground floor. And then, I went to the basement, and realized there were at least 2.5x as many! I really wanted to buy a multitude here, but I would not have had room in my suitcase, so I had to refrain.
Enter at your own risk I'd say. It has a great selection of great books and should be somewhere you stop with caution in Trondheim.