One of the trees planted along the sidewalk is emitting a soft glow that cycles slowly through the rainbow.

What.

The tree keeps doing what it's doing! Another pedestrian passes it without remark.

So. Obviously she wants to figure out what's going on. But there's a high likelihood that "what's going on" is that she's seeing things! And—she doesn't really want to draw attention to what she's seeing if other people don't see it, or at least think it's so unremarkable that it isn't worth glancing at.

She takes out her phone and types in a quick note for herself describing the precise location of the glowy tree. Then she closes the notes app, rounds the nearest corner, and distracts herself until she's fairly confident that she doesn't actually remember which tree was behaving suspiciously.

And then she turns around so she can check.

Well, there's still a tree that's doing the thing, though it's less obvious from where she's standing. If she approaches she can confirm that it's in the same spot as before. The light show doesn't show up on her phone camera.

This doesn't exactly fill her with confidence that she isn't hallucinating! And she does still have a grocery run to complete.

She passes by the tree on her way home.

It's still doing the thing.

She watches the light show cycle through the rainbow, then carefully touches the trunk.

Her hand passes through the bark as though it isn't there.

Her first impulse is to stick it in deeper. What she actually does is withdraw her hand and get out a pen she can use to investigate.

The pen goes in just like her hand did.

She's still a little cautious about sticking her whole hand into the Mystery Space, but having a stick to poke things with directly helps. Can she put her hand all the way through the tree?

Nope!

… The fuck? She can feel a curved wall opposite where she stuck her hand in, but it's farther in than the tree is wide.

She pulls her hand back out and touches the other side of the tree.

The same thing happens on the other side: her pen goes in and hits a wall.

She repeats the experiment at various places on the tree. Different angles, different heights.

The same thing happens regardless of where she puts her hand in.

She takes out her phone and starts recording a video. She really hopes that she won't need to explain to her mother in half an hour that she needs a new phone because she stuck it into a weird bigger-on-the-inside tree on the way home from the grocery store.

Well, the phone doesn't mysteriously vanish from her hand when she puts it in the tree!

That's not really what she's worried about! She turns her wrist; she wants to get good video of the bottom, top, and sides of… whatever this is.

Her phone is still perfectly functional when she pulls it out. Still recording video, too.

Oh, good, she hasn't immediately fried her phone. She stops the recording and pulls it up to watch.

It's a little trippy when the video clips through the tree's bark like some sort of computer graphic. The inside of the space is a squat cylinder reminiscent of a tuna can, if a tuna can was hollow, made of smooth wood, and clearly illuminated by no apparent light source.

Also, there's a paper packet on the bottom of this space that says "open me!"

This is almost certainly a bad idea. She hasn't thought of any ways to test whether this is a trap, much less applied those ideas, so obviously she has to start from the assumption that it is one.

But.

Even if it is a trap, it's easily the most interesting thing that's ever happened to her. And she's been standing here for a few minutes; her mom will probably be texting her soon to check up on her. What if it's gone when she leaves?

No, he shouldn't succumb to time pressure. Besides, the weird tree stayed put the entire time she was at the grocery store.

Her real worry, of course, is that someone else will take it first. Logically speaking, though, nobody's particularly likely to take it in the next twenty minutes. At least, no more likely than they were any time before now. She's got no idea, after all, how long this has been here.

She closes her eyes and turns her back to the tree. Counts out a full minute under her breath before turning to look again.

Nothing's changed about the tree.