Master Mills first encountered Heather Longtreader after an incident with a bricksplitter left him with a deep gash in his midsection. After careful treatment, he was deemed irremediable by Doctor Hendow and Mills was left in the surgery while his family was informed. On an impulse, Heather gave the unconscious buck a dose of Aunt Jone's tonic.
Later, Heather believed that she saw Master Mills assisting in the evacuation of the Akolanians on Victory Day.
While attempting to heal her wounds with Jone Wissel's tonic in the Tomb of Lander's Dragons, Heather Longtreader remembered what a perilous case Mills, her last patient, had been, and how she had used the tonic on him. She had later seen Mills' twin brother fighting during the Victory Day revolt.
As she slipped into unconsciousness, Heather wondered vaguely if Jone's tonic really was some sort of miraculous cure, and if Mills had no twin brother, as she had originally believed, but if it had been Mills himself she had seen fighting. Spurred by this hope, Heather treated Smalls with the tonic, then fell unconscious.
- The name "Mills" is of English origin and was bestowed upon those who worked in a mill.