NSFW (Nudity) content and manga spoilers ahead.
Those are White Birch Branches. It's also mentioned in the manga during Chapter 20.
I'm not sure of their exact use but according to the Wikipedia page of birches,
fragrant twigs of silver birch are used in saunas to relax the muscles.
This seems to coincide with what is shown in the manga/anime, as it ...
The term for these is a bath broom.
Or "banny venik" (from банный веник) in Russia.
Or "vasta" or "vihta" (depending on the region) in Finland.
(image by kallerna [CC BY-SA 3.0 or GFDL], from Wikimedia Commons)
They're mostly used in heated bath houses and, prior to refridgeration, were a rather seasonal luxury. You use them, quite simply, just to hit ...
What is it? Well, the following conversation happened on the same chapter, Chapter 29:
Goblin Slayer: You knew everything, didn't you?
Sword Maiden: What do you mean 'everything'?
Goblin Slayer: The cause and the extent of the goblin nest in the sewers. Maybe even who's behind it.
Sword Maiden: Yes...Yes, I did.
Contrary to the other ...
Yes, she is blind. In Volume 2 Chapter 7 of the light novel, it was indirectly stated that she is. To quote,
Sword Maiden didn’t answer. With her blind eyes, she stared at a person who seemed to her a shadow.
Also, in that same volume at Chapter 12, it was revealed how her eyes were blinded.
She had been shut up in a dark stone chamber, riddled with ...
From the wiki:
Episodes 1 to 4: Manga Chapters 1-9 and Light Novel Volume 1
Episode 5: Manga Chapters 10 and 17, Light Novel Volumes 1, 2 and 4; and Goblin Slayer Brand New Day Chapter 1
Episodes 6 to 9: Manga Chapters 17 to 29 and Light Novel Volume 2
Episodes 10 to 12: Manga Chapters 10 to 15 and Light Novel Volume 1
The Goblin Slayer novel currently has ...
Goblin Slayer has been an active adventurer for 5 years at the beginning of the story. Sword Maiden defeated the Demon Lord with the Heroes and became gold-rank 10 years prior to the events of vol. 2. So, for Sword Maiden to be captured and then saved by Goblin Slayer, it would have happened way after she's famous as a gold-rank adventurer. I don't think it'...
Since this question have a lot question, I'll break it down.
Q:In Chapter 29, the sword maiden seems to "know" something that she didn't share with Goblin Slayer's team.
A: Yes, Sword Maiden did know something happen below the city and also lie to Goblin Slayer's team about the rat quests. The rat quest is just a fake quest. The real quest is the Sword ...