13a. " I go back to the end of the questio word to start" says the wise one (4)
27a Act of generosity sends king endlessly astray (8)
29a. Call a plumber an insipid one? (4)
24a. /15a. Among others I alter in a translation (5, 4)
23d Sourcing kublai Khan; X marks the spot and a u-turn(6)
27d. Unable it seems to name the philosopher (4)