The Glass Unicorn, Part 6 by Yasmine Galenorn

When Erenye Green, an editor at a small publisher, and several of her gaming friends find themselves stuck within the fantasy world of Abarria, they must learn to navigate the realities of what it really means to battle monsters, zombies, and all manner of creatures, now that the stakes are life and death, and no longer a simple roll of the dice.

Part 6: Erenye and the others leave for the Cryptic Marshes and get waylaid by a mysterious guardian along the way.

Notes:
This is a LitRPG serial.
Part 6 of the Glass Unicorn (A Quest Wars Adventure)