SEXTON BLAKE'S assistant, Tinker, was, in his younger days, a newspaper-seller in London's East End, and it was there that he met the girl who was to become known to fame in later years as Nirvana, the famous dancer. Unknown by him, save as the victim of her elder sister's teaching, he saved her as a young child from arrest for picking pockets. Their ways parted, and years after, when she had climbed to world-wide fame as a stage artiste and Tinker had long been the assistant of Sexton Blake, they met again. Events were to prove that Nirvana was still a thief -a thief by the compulsion of her fiendish sister, Marie. He tried, and succeeded, to restore goods that she had stolen, and even nearly succeeded in reforming the girl herself by an appeal based on their common past. But Marie triumphed, and Nirvana remained in the toils. His part in the affair Tinker kept a secret from his master, but Sexton Blake knew more than ever Tinker guessed.