The Adventure Begins

The Adventure Begins was an Audio Episode set before the events of ERAS Series 1, produced by Gearhead Media as an introduction to the Alternate Thirteenth Doctor played by Aiden Caufield, and began in 2020.

Background
The Audio Episode begins with the Twelfth Doctor [Peter Capaldi] saying his farewell as the Doctor at the end of Twice upon a Time, an Episode aired on television within the BBC Series 'Doctor Who', and later regenerating into the show's [ERAS] first original Doctor, their Alternate Thirteenth Doctor, known as Aiden Caufield.

As the TARDIS begins to crashland, we get the usual crash landing speech from the new Doctor, and it continues into the first Episode of ERAS Series 1, the Fade.

Episode Breakdown
After The Twelfth Doctor then returns to the TARDIS and decides it's now time to regenerate, but not before relaying advice to his next incarnation, the Twelfth Doctor finally lays himself down to rest and regenerates into a new incarnation of the Doctor. Though, not the incarnation that was expected, he regenerates into an Alternate Thirteenth Doctor.

After the newly regenerated Thirteenth Doctor thanks his prior incarnation for advice, begins checking his appearance based on touch alone, and then finally notices that his prior incarnation caused an explosion that is destroying the TARDIS control room, which is suffering multiple system failures due to damage caused by the delayed regeneration, and hurtling him and his time machine towards the Earth below.

This incarnation of the Doctor, played by Aiden Caufield, crash-lands his TARDIS on the outskirts of an English Village called Chopwell, within the United Kingom's North East. The Doctor leaves the TARDIS to self-repair, but due to the major damage the TARDIS disappears, and the Doctor falls unconscious, taking roughly an hour to recover enough to roam around and stand at least.