Making Magic: The Sweet Life of a Witch Who Knows an Infinite MP Loophole Vol. 4 (light novel)

After being forced to say their goodbyes to Selene, Chise and Teto return to the Wasteland of Nothingness with heavy hearts. To curb their loneliness, the pair preoccupy themselves with building a new home and aiding Prince Gyunton in breaking a secret network of slavers operating in Gald. Their work is put on hold, however, when a strange drain on Chise’s mana restoration project in the Wasteland reveals a precursor ruin practically underfoot! Home and garden will have to wait! Adventure calls, and waiting in those sunken vaults, an enigmatic new friend in need of mending—a task that may prove impossible even for Chise.