The Path of Knowledge (quest)

Walkthrough
Storn Crag-Strider reveals that recently a wizard named Neloth visited Skaal Village looking for a Black Book. So it stands to reason to look into matter, since such books are closely related to Miraak's powers.

Talk to Neloth
Talking to Neloth in Tel Mithryn indeed turns out to be helpful, since the wizard knows of a book containing another word for the Bend Will shout, and he even knows that it is located at Nchardak to which he has the key. Trouble is that more such control cube keys are required to unlock the book.

Travel to Nchardak with Neloth
And so the Neloth and the Dragonborn travel to Nchardak.

Restore the steam supply to the Dwemer reading room
To unlock the Black Book at the Nchardak Reading Room the steam supply to the room needs to be restored. But for this more control cubes are required. So the ruins need to be explored and a few puzzles solved.

Release the book from the Dwemer contraption
Finally, all five control cubes have been found, and placed in the proper receptors, diverting steam to the Reading Chamber. The Black Book: Epistolary Acumen is unlocked and it is up to the Dragonborn to read the book in The Gardener of Men.

Der Weg des Wissens (Aufgabe)