Can you recount the story of the serpent in the Chavadi and how Sai Baba saved his devotees?

Certainly. The Chavadi serpent incident is a powerful example of Sai Baba's protective nature. As told in Chapter 22, Baba was sleeping in his usual spot, which was always lit by lamps, while his devotees slept in the dark outer region. At midnight, he began shouting for his devotee Abdul, claiming a 'vivashi' or phantom was near his bedding. When Abdul couldn't find anything, Baba insisted and struck the ground with his satka, waking everyone. An experienced devotee, Amir Shakkar, understood Baba's cryptic language, realizing that Baba was warning of a danger near a devotee, not himself. Amir then found a large, venomous snake near his own pillow. He called for the lamp, and the light dazed the snake, which was then killed, thus saving him from a fatal bite.