[s10e6] Extremis Instant

The Doctor (Peter Capaldi) discovers that the "real world" he is in is actually an incredibly detailed computer simulation created by an alien race known as the Monks.

The episode's central mystery involves the , an ancient text in the Vatican's secret library that causes anyone who reads it to commit suicide. [S10E6] Extremis

Upon realizing he is a "simulacrum," the virtual Doctor uses his sonic sunglasses to record the entire experience and emails it to the real Doctor in the physical world as a warning of the impending invasion. The Vault & Missy The Doctor (Peter Capaldi) discovers that the "real