You can find it on Amazon.com here:
https://www.amazon.com/dp/B0CW922JXZ/ref=sr_1_11?dib=eyJ2IjoiMSJ9.lxahnzsK9EVKmmdEOP80CX93Ru-hjtUKdczhKeJgwp3XW-uZXlNULV0ObV6lZxFDhw0De0b1N-t7okF46Y-XEtfJb06N1XySZYu-Zs1jMPkq7ZJ_EuPz9KkGl6Zur2pRDnu2oKwObsNQkiXiyRVSwT_dYXR1bSTaZjk8g6VcZ6zZZXUJu1QGmbOUBMIIppydXFbMfhZSlrvQJDp7_zj5_ZImkZDT_sankcabWqBItA8.8-I4KmZIim1HlHQAhXwp_DItegDFGiHep2aE12kurik&dib_tag=se&keywords=under+the+mountain&s=digital-text&sr=1-11
Details:
Sarka and her new companions travel to Amyalneas to swing by the Great Library. Instead of being a simple side quest, the situation goes south really quickly.
Startum Ironwolf and friends arrive in Aeroch Nor for the evening. The plan is simple. They want to sell their loot, do some shopping, get Zeven his polearm, and log out for the night. Before they even reach the Hammertoe Clan's cavern, trouble rears its ugly head.
In other parts of The World, Hollysharp finally gets theHollyTerror underway. The rest of Star's friends reach Delonshire to the shock of Delonshire Guard Captain Miya Faelwen. And back in BrokenFang Hold, the Valkyrie and Devil Dogs guild have come up with an audacious plan.