The Veil was the third The Blogs of Doom short story, published in January of 2018 in Doctor Who Magazine 521. Like other features in the series, it narrated events in the life of a minor Doctor Who TV character before and after their involvement in the Doctor's life, turning everything the readers thought they knew about them on its head.
In this case, the subject of writer Jonathan Morris's attention was the silent, stalking Veil from Heaven Sent, revealed (in first-person perspective as a series of log entries) as a generally benevolent entity obeying its orders, but wishing the Doctor no harm, and who actually tries to help him as the loops go on and it realises it is as much a prisoner of the confession dial as the Doctor.
In essence, The Veil thus retold the events of Heaven Sent with a flipped perspective, although it would perhaps be rather too much to call it a novelisation of the TV story, especially as it did not include the cliffhanger ending.
When the Veil is ordered by its powerful masters to take the shape of the Doctor's greatest fear and get the secret of the Hybrid out of him, it expects the job won't take long, and hopes it can do it without getting on the Doctor's bad side. As the Doctor arranges an endlessly-repeating loop of death and resurrection with the confession dial, the Veil begins to reconsider its priorities.
On the Veil's first day inside its allotted new position inside the Twelfth Doctor's confession dial, it starts a log where it describes the castle it now has to inhabit and its mission: to get the Doctor (about whom it has been told by its masters, and far from all good things at that) to confess what he knows about the Hybrid. The Veil promises itself to try and gain the Doctor's friendship if it can, and hopes that the job won't take long at any rate.
After the Doctor arrives, the Veil follows him silently for some time and takes on a form based on his worst nightmare, that of a veiled, lurching corpse with flies buzzing around it. It manages to get him to confess that he's scared of dying, and finds itself teleported back to the start, to its confusion. When it catches up with the Doctor again, the Doctor jumps out of a window, but can't escape for long, with the Veil managing to get him to say that he left Gallifrey because he was scared, which once more sends the Veil back where it started.
The final confusion he gets out of the Doctor, having caught him at the top of the castle, is that he does at least know what the Hybrid is. After that however, the Doctor finds Room 12, where he begins to punch the azbantium wall. Worried that the Doctor is trying to put himself out of commission, the Veil grabs at him to hold him away from the wall, and belatedly realises that its touch is lethal to its prisoner, who begins dying while the Veil finds itself sent, once again, back to Square One. The Doctor, meanwhile, crawls his painful way to the teleport room to kill himself and create a new version of himself to carry on the cat-and-mouse game.
Thus, on the second day, much the same things happen to the Veil's mild irritation, an irritation compounded by the new Doctor hypothesising that the closed energy loop means the room reset themselves — when in truth it is the Veil who must, by hand, do such things as refill the hole in the garden, light the fire, repair the bedroom window and prepare the Doctor's food. A few identical days later, the Veil starts to catch up to what is going on, and, in frustration, stops taking logs — a decision which holds fast except for one day where it notes that it and the Doctor inexplicably spotted a pigeon in the rafters.
By the beginning 7000th year, the Veil has realised that it's as much a prisoner as the Doctor, and decides to help speed up his escape. It figures out that a good way to improve the Doctor's stable-loop plan would be for him to use the spade in the garden to hit the wall, rather than his bare fists. However, over the following thousands of loops, the Veil can't figure out a way to point the spade out to the Doctor without the Doctor assuming that it's some sort of trap, and by the 7th day of Year 200435, it gives up altogether.
Time passes, and finally, on the 42nd day of Year 4,500,000,003, the Veil adds one last entry to its log, noting jubilantly that the Doctor needs only one more punch to the wall before breaking out, and hoping that the Doctor (of whom the Veil has grown fond over these seconds in eternity) will take it with him when he does escape.
- The story addresses a common criticism of Heaven Sent's plot structure, namely the Doctor's failure to use the spade to bash down the wall instead of the more painful option of his fists.