Read in the UK around 2013–2014. Contemporary vibe, teens had phones. Opens near a skatepark. A boy is sentenced by a shadowy authority to a prison in a pocket universe, basically a floating rock. The prisoners are mostly teens and don’t age while inside. Time outside moves slower, and when a sentence ends the prisoner returns to the same moment they left, so no one believes they were gone. There’s a warden figure. I remember an apple being given as a small act of kindness. The boy falls for a girl who turns out to be a mole for the authorities in exchange for a shorter sentence. In the end she decides to stay to enable an escape, and the boy chooses to stay with her. Final image is the two of them looking out over a desolate landscape, and the passage is closed, trapping them. Not: Incarceron, Escape from Furnace, Darkside, TimeRiders, The Loop. Any ideas?
1 Answer
This sounds very much like The Traitors, a YA novel by Tom Becker, first published in 2012.
The protagonist is called Adam. On the charge of "betraying a friend" he is sentenced to spend two hundred and seventy-four years in a futuristic prison for young offenders, known only as the Dial. It is described as existing in different dimensions:
The Dial is located in no-time, a place far beyond the outer reaches of the known universe. Although the seasons turn as normal, the Dial’s planet must revolve around a different sun, for a year here lasts as long as a blink of an eye back on Earth. The prison can only be reached through a warphole in the sky, which is activated by the machinery located in the Commandant’s Quarters. If anything or anyone else exists in no-time beyond the prison walls, then it has remained hidden. As far as we know, this world is entirely barren. There is only the Dial.
While they are in the prison, the children do not age. When their sentence is complete:
inmates are taken to the Re-education Wing, where their minds are wiped of all memories of the prison, save for a flicker on the edge of their consciousness. They are left only with an awareness of the steep price of betrayal, an awareness that prevents them from even thinking about committing the same crime again. Then the inmates are allowed to resume their life on Earth, not looking a day older than when they left, and where barely a second will have passed since their arrest. After that, it is hoped that they will live their lives with a sense of honour and loyalty instilled by countless decades of imprisonment.
The text I have bolded matches the OP's recollection very well.
Adam indeed falls for a girl, Jessica, who is an informant for the prison authorities. The story concludes with the children successfully escaping from the Dial through the warphole, but Adam and Jessica stay behind after realising they are truly in love with each other. The final scene is of the two of them looking out over the ruined landscape of the Dial:
On the other side of the prison, two figures could be seen sitting on the perimeter wall, their feet dangling over the edge. Their hands were locked tightly together. As the last of the flames crackled out, a soft giggle could be heard as the two traitors inched closer to each other, settling down to share an eternity of forgiveness.
