The Nine Unknown by Talbot Mundy

It was Grim, returning from the Chandni Chowk that afternoon, awaking them one by one, who summoned another conference in Ghandava's great, cool library. Ghandava had disappeared, but the smell of artful cookery ascended from below-stairs, and the green-lined _chela_ kept himself in evidence at intervals, incurious and yet alert. He never seemed to listen, nor to keep from listening, but hovered in and out like a house-mouse busy with affairs behind the scenes. Once he was gone for a whole hour.

"Giving my imagination utmost creeps!" as Chullunder Ghose remarked.