One of the many reasons I studiously avoid spoilers is for situations such as my reading of this play. I had heard of the play, of course, but I had never read it nor had I seen a stage production of it. Before I read it I knew nothing about it except that it is considered a classic and it was originally written in Norwegian.
Reader, I am so glad I knew nothing going in, because I was really stunned by what I read. When I started reading, I began to expect the story to go in a certain way based on my preconceptions of a play originally written in 1879. In fact, the story turned my expectations on their head and the ending left me gobsmacked. This is such a "contemporary" play that if my copy of it hadn't been included in a book that was originally published around 1900 I would have assumed the play was written in the mid-20th century at the earliest. And this is the power of going into a book "blind" and letting it wash over you - you're free to be gobsmacked at the end of it all.
If you haven't read this play you should go over to Project Gutenberg, as I suspect they've covered it, and check it out; it's a short read and well worth the reading, if only to marvel at. I suspect it influenced a lot of other writers. The background of the play and its origins are fascinating too. Now I really must read some more Ibsen, once I clear off this crazy TBR pile once and for all. Highly recommended.