The Doctor is most likely one of the main characters. There could also be his companions, though without more specific knowledge about this short story, it's hard to say exactly who else.
The main character is bound to be the Doctor. His role would be to investigate the mystery of the 'ghost in the machine'. Alongside him, his companions, if present, would play important parts. There might also be antagonists, which could be the source of the 'ghost' in the machine, whether it's an alien entity using the machine for its own ends or a malfunctioning AI that has turned hostile. These characters would all interact with the Doctor as he tries to figure out what's going on and put an end to the strange happenings.
Chapter 354, "Mr. Luo, Aren't We Unfamiliar?", is the clearest early answer because it turns Miss Jin Zhen's situation into a concrete plot event. The chapter gives readers a real answer by opening on Lin Manru simply couldn't believe what she had heard.
Chapter 366, "The Safety Lock Got Flattened?!", is the clearest early answer because it turns Xiao Wu's situation into a concrete plot event. A useful checkpoint is the way the scene starts with You're finally out!" Xiao Wu saw Jiang Li and the others from a...
Chapter 350, "The Male Lead Actually Came Out to Clear Jiang Li's Name?!", is the clearest early answer because it turns Xiao Ling's situation into a concrete plot event. Early on, The criticism on Weibo continued to ferment..
Chapter 196, "I am the one with the most potential!", is the clearest early answer because it turns Wen Jiaojiao's situation into a concrete plot event. The chapter gives readers a real answer by opening on Wen Jiaojiao was on the verge of a breakdown.
Chapter 247, "Madam, Your 2000 Kilograms of Sweet Potatoes, Please Check and Accept", is the clearest early answer because it turns Shu Yan's situation into a concrete plot event. It opens with Facts have proved that arch-enemies often understand each other the...
Chapter 365, "Are You Sick?", is the clearest early answer because it turns Su Yinwan's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Jiang Li didn't make a sound, she merely glanced in the direction of...
Chapter 544, "I Shouldn't Have Stopped You from Pursuing Shang Shaojing Back Then", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event.
Chapter 397, "Talent Show Program", is the clearest early answer because it turns Zhou Wenshu's situation into a concrete plot event. The chapter gives readers a real answer by opening on Second Aunt, I know you're worried about Shixu interacting with...
Chapter 343, "He Can Support Jiang Li for a Lifetime", is the clearest early answer because it turns Lifetime Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from But she suddenly acted mischievously indifferent, "Are you a...
Chapter 396, "The Shang Family Now Follows My Orders", is the clearest early answer because it turns Shang Shaojing's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Doomsday Beehive" featured a male supporting character who was...