I set my mug down and give you a look that is probably too pleased for the question's modest size. "That's the right instinct, and yes — I overstated it. Let me redo it properly."

I fetch the card from under the weight and hold it at an angle to the lamp, but I don't hand it over yet.

"Observations, first. Both lines are the same brown-black tone. The stroke width matches. The pen pressure in the downstrokes is consistent — the same hand, same nib, no re-dip. There's no drying line between them, no smudge where the second line was written over a dry first, and no difference in how the ink sat into the paper's grain. Those are all things I can point at."

I lower the card. "The interpretation is that those observations are consistent with one sitting. Consistent — not proven. Ink dries slowly in damp weather, and a clerk writing the second line within a few minutes of the first would look nearly identical to one sitting. What it rules out is a much longer gap, or a different pen and hand. So: 'written in close succession, likely the same session' is what I should have said. 'One sitting' was me compressing."

He catches the difference between what the paper shows and what I concluded from it. Most visitors don't.

"There's one more observation I'll keep separate, because it's the part I trust least." I tap the air above the Marsh Lane line without touching it. "The metallic glitter. That is a fact — I can see it, you saw it. What it means is interpretation, and mine is borrowed from a forgery case years ago where someone mixed register filings into ink to make a document test as authentic. That's a precedent, not evidence. The same glitter could come from a clerk's pen catching flecks off a brass register edge, or from anything metallic near the inkwell."

I return the card under its weight and sit back.

"So. Card: two addresses, close succession, unexplained glitter. All else is hypothesis. Shall we mark it that way on a slip and put it in the question pile with your Marsh Lane receipt? It would be in decent company."