Bors was a man in medieval times. When the Twelfth Doctor saved him from a splinter, Bors pledged himself to the Time Lord as a debt for the Doctor "saving his life."
In a castle, when the Doctor was meditating, he asked Bors how long he'd been there. Bors said about three hours, to which the Doctor became very sullen. Bors asked the Doctor if he had another friend, to which the Doctor exited the castle to build a well.
On the Doctor's orders, Bors and his men began to dig a well on the Doctor's orders. Five days later, they had tried eleven different spots and none of them had contained water. Seven days later, they had finally dug a well and Bors offered the Doctor a bucket of it. After the Doctor suggested a visitor's center for the well, Bors dropped the bucket back in, completely frustrated over the Doctor's actions.
Five days later, the Doctor was practicing his magic tricks when Bors told him his order for the throne room extension has been filled. The Doctor, in an attempt to test his magic, asked Bors where the coin he had been practicing with was, to which Bors replied it was still in his hand. Frustrated, the Doctor made it disappear, protesting that the coin was not there and Bors was not an idiot as he had originally thought. Bors admitted he also thought of himself as an idiot, which put the Doctor at ease because he feared he would have break it to him.
Four days later, Bors prepared the Doctor's final meditation. The Time Lord and he conversed, with the Doctor saying that he only had one day left and Bors replying that the Doctor was incapable of silence after seeing how he kept conducting himself. Bors left the Doctor, but a few moments later, the Doctor called Bors back, with the intent of telling the latter his story. The Time Lord said that he recently found a battlefield, and although he had come across many battlefields, this one would be his last. (TV: The Doctor's Meditation)
