Tress of the Emerald Sea sounded like such a fun read, that I ended up getting it when I was last out book shopping.
Tress is a window washer who lives on a tiny island on the verdant spore seas. She has no interest in adventure; all she wants to do is live her life and visit with Charlie. Charlie is the Duke's son, who pretends he is a gardener whenever Tress is around so they can hang out (even though she knows who he really is). But when the Duke sees them together, he takes Charlie on a tour of the kingdom to find an eligible bride. But when the Duke returns with his heir and daughter-in-law, Tress is flabbergasted to find that the heir in question is NOT Charlie. After some prying, she discovers that Charlie was sent to the Sorceress of the midnight sea. He was captured, but no one seems interested in paying his ransom. And so Tress, in her methodical way, sets out to rescue him.
Tress of the Emerald Sea was such a delight to read. The tone of the book is very whimsical (thanks to the narrator, Hoid); it reminded me a lot of Stardust by Neil Gaiman (and the cover of the book compares it to The Princess Bride, which seems apt as well). Tress is a wonderful character who I really enjoyed spending time with. She also meets some really interesting characters (Fort, Ann, Salay, and Huck) who I really liked too. They were all delightful people to spend some time with. :)
The setting of Tress of the Emerald Sea was really interesting as well. The moons of the planet dump spores onto the planet. The spores activate with water, and do different things depending on their colour (the green ones, for example, became vines). Unfortunately the human body is full of water, so if the spores come into contact with you, they can kill you. But the spores can also be sailed on, so humans have built boats (with silver protections, because silver kills the spores) to sail around the world.
I've now read a couple of novels and novellas by Sanderson, and haven't been disappointed yet. Tress of the Emerald Sea was another fantastic story by him, and I am excited to one day read more. :)