A cross-examination game
SWORN
The witness is lying. Prove it — to a machine that can actually check.
3 cases · Cardle Head Observatory · the night of 14 March 1974
Headphones recommended — every line is spoken.
“The control room. From half past ten onward. I did not move from that chair until the ambulance came.”
“Because I saw him. He was up on the gantry, leaning out over the rail, and then he was not there any more.”
Could not have seen it from there
- Dr Ashgrove says she saw Dr Nix on the gantry, 22:48–22:51
- Dr Ashgrove says she was in the control room, 22:30–23:10
- the Gantry is in view only from the Dome Floor — or from standing on it
The Gantry cannot be seen from the Control Room.
01 — Nothing is scripted
Every sentence a witness says compiles into a formal claim: who, where, from when to when. Every exhibit asserts a fact in the same shape. No case file anywhere says which pairing is the right answer.
02 — The map is physics
The headland has real walking times and real sightlines. When a witness is placed on the cliff path at 22:47 and her hand is on the gantry rail at 22:48, the solver knows that walk takes five minutes — and says so.
03 — Proofs, not cutscenes
When you catch someone you get the derivation: the minimal set of statements that cannot all be true, and the arithmetic that makes it so. You can check the game’s working.
Three people were on the headland.
At ten minutes to eleven, the director of the Meridian Observatory fell twenty-two feet from the dome gantry onto the concrete below. Three people were on the headland. You are the coroner's officer, and you have until morning.
Ivy Wren
Assistant astronomer
Twenty-six, three years at the Meridian, and the only person on the headland who understood what Nix was actually photographing.
voiced · Imogen
Samuel Tolliver
Warden
Thirty-one years on Cardle Head. Keeps the generator, the gate and the grass, and has opinions about all three.
voiced · Alistair
Dr Constance Ashgrove
Trustee
Signs the cheques that keep the Meridian standing. Drove three hours that evening to tell Nix the money was stopping.
voiced · Vesper
All three lie to you. Only one is lying about the gantry.
What the solver knows how to catch
Two places at once
Overlapping intervals, different rooms.
Not enough time to walk it
Shortest paths over the site plan, in minutes.
Could not have seen it from there
Sightlines are physical facts, and they are checked.
The thing seen was elsewhere
Perception implies presence — for the thing perceived, too.
Placed where they were not
A door log is not an opinion.
Two states at once
The mains cannot be dead and live together.
The instrument could not have run
A dome does not rotate on a dead supply.
Perception forward-chains into presence, so a proof can run three deep: what she says she saw implies where he was, which collides with a log she never thought about.