I asked my upstairs neighbour three times to stop throwing used tea bags onto my balcony. The third time he laughed at me. So I stopped asking, and I spent an afternoon getting ready instead.

I had the dates. That is the part people find odd and it is the whole reason it worked.

I had been writing them in the back of a notebook since the towel. Not because I was building a case. Because after the first upstairs conversation I had wanted to know whether I was exaggerating, and the only way to know that was to count.

Thirty-eight dates. Thirty-eight times.

I had started that notebook on a Thursday in the June and the first entry is in a different pen from the rest.

It says, underneath the date: am I being ridiculous?

I have not crossed it out and I am not going to. It is the first line of the only document that mattered, and it is a woman asking herself whether she is allowed to mind.

By the eleventh entry I had stopped writing anything except numbers.That is what counting does. It takes the question away from your feelings, where it can be argued with forever, and puts it somewhere it can be settled.

And there is a page in the middle where there are two entries in one morning, which is the only anomaly in the entire notebook, and which I have never been able to explain.

The eighteenth of August. 7:02 and 7:39.

Two of them, thirty-seven minutes apart.

I have decided he made a second cup. I prefer that to the alternative, which is that he came back out specifically.
PART 4

The next morning I was outside by five to seven with a coffee and my phone within reach and absolutely no intention of knocking on 4B a fourth time.

At three minutes past, I heard movement above me. Then his balcony door slid open.

I waited.

A minute later his hand came over the railing with something small dangling from it, and the tea bag dropped.

And this time I did not sigh and throw it away.I picked it up with a pair of kitchen tongs, put it in a freezer bag, went inside and wrote the thirty-ninth label.

Then I carried the board down to the shared drying yard and set it on an easel.

Thirty-nine tea bags, pinned in rows.

Under each one, a small white label. Date. Time. Nothing else.

And here is the part that made it work, and I did think about it for a long time at that kitchen table, and I want credit for exactly this and nothing else.